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Home Gardeners: Providing you with useful information to keep your garden blooming

Here is the feeding program Jack’s recommends for growing tomatoes.

  • After transplanting the tomatoes, I want to get them off to a great start. In order to do that you need to provide plenty of phosphorus to the root system which has not yet spread out in the soil. I use the Jack’s Classic® Blossom Booster 10-30-20 at 1 tablespoon per gallon when I set the plants in place.
  • After the first week I come back and make my first application of Jack’s Classic® Tomato FeED 12-15-30. This is just what the plant needs to grow in mass with plenty of new leaves and thick stems that will be the factories to produce lots of energy that will give you a high fruit yield. This new fertilizer conations calcium and magnesium for hungry tomatoes. I repeat these feedings every 10 days to make certain there are no nutrient stresses to hold back production.
  • After the first month I switch my feeding program to a combination of 1 tablespoon of 12-15-30 and 1 tablespoon of 10-30-20 in 2 gallons. Stick with this combination until all your fruit is set and the first of the fruit is starting to turn red
  • From this point on I stick with the Blossom Booster 10-30-20. The high potassium will let the fruit finish nicely. Apply the fertilizers every 10 days or so right through the end of the crop.

Everything you need to know to care for your African Violets

Soil: African violets like a well-drained soil and there are some good prepared soil mixes on the market specifically for African violets.

Temperature and humidity: Both temperature and humidity are important factors for success with African violets. Daytime temperatures should be around 70-75 degrees and night temperatures perhaps a few degrees lower. Adequate humidity for plants is a problem in the modern house. Placing the African violets on a pan full of pebbles can cure this. Keep water in the pebbles but never let it touch the bottom of the pot. Humidity is achieved through the evaporating water that creates a mini-climate around the plant. The best humidity range for African violets is 60-70%.

Light: The light requirements of African violets are easy to satisfy. Indirect light is the answer for these plants. If the sun casts a shadow when something is held between the sun and the plant, the light is too strong.

Watering: Watering African violets is a simple procedure. Keep water off the leaves and use only room temperature water to prevent water spots on the leaves. Water these plants when the soil mixture feels dry on the surface.

Fertilizer: To maintain your African violets in top condition a fertilizing program is a good idea. The young plant should be given water-soluble, balanced fertilizer such as Jack’s Classic All Purpose 20-20-20 at ¼ teaspoon per gallon at every watering. When encouraging flowering, fertilize with Jack’s Classic African Violet 12-36-14 at ¼ teaspoon per gallon at every watering. Young plants should have their flower buds pinched off to encourage vegetative growth. When the plant has reached a good size with strong foliage, switch to 12-36-14 fertilizer and allow the plant to bloom.

Few flowering houseplants prove as frustrating to the indoor gardener as gardenia. However, if you provide the proper light, humidity and temperature conditions, you can regulate the quantity, time and length of bloom.

FACTORS REQUIRED FOR BLOOM

The most critical factor in encouraging your gardenia to bloom is TEMPERATURE. Gardenias do not produce flower buds at evening temperatures above 60 to 62 F. If the night temperature is kept at 60 to 62 F, the plant will bloom continuously.

Also essential to flower production is sunlight. In fact, the number of flowers on a gardenia is directly proportional to the light intensity. When you grow a gardenia in the shade, its leaves are thin and weak producing insufficient plant food to develop flower buds.

Finally, gardenias like a high relative humidity. In a greenhouse where water is splashed about or mist systems are often installed, this is no problem. In your home, air conditioning and heating units decrease the relative humidity, often resulting in bud loss. You can counteract this problem by setting the pots on trays of moistened pebbles, peat moss, sand, perlite or sawdust.

FERTILIZER REQUIREMENTS

Fertilize your gardenia monthly with Jack’s Classic® Houseplant Special 15-30-15. For hard water or to lower the pH of your soil, try Jack’s Classic®

Acid Special 17-6-6.

Choose one of the following application rates:

  • ½ Teaspoon per gallon of water every other week OR
  • ¼ Teaspoon per gallon every time you water your plants.

Note: You can use a 1 gallon empty water/milk container to make your fertilizer solution. Water as directed. Store the rest for later use.

KEEP THE SOIL MOIST

Without continuous growth your gardenia will stop blooming. If it dries out between waterings or becomes soggy, your gardenia will drop its buds first and its older leaves a week or so later. You can make a good well-drained potting mix from 2 parts peat moss, 1 part coarse sand or perlite and 1 part potting soil. During prolonged cloudy weather supplement natural lighting with a grow light.

Use:20-20-20 All Purpose, or 17-6-6 Acid Special or 10-30-20 Blossom Booster
Rates:1 Tablespoon per gallon, or 4 oz/gallon with a Hozon (1:15), or 27 oz/gallon (1:100)
Sept.10-30-20 Blossom Booster (optional)
When:SpringAprilInitial Feed17-6-6 Acid Special (especially if chlorotic)
  May4 weeks10-30-20 Blossom Booster
 New GrowthJune4 weeks17-6-6 Acid Special
  July4 weeks17-6-6 or 10-30-20
 Hardening offAug.4 weeks10-30-20 Blossom Booster
  4 weeks

Note: You can substitute 20-20-20 All Purpose for 17-6-6 Acid Special where pH Control and sulfur availability are not a problem.

OTHER NUTRITIONAL TIPS

Bedding Plants: Use 20-20-20 All Purpose or 10-30-20 Blossom Booster every two weeks. Watch the lower leaves for yellowing to determine product and frequency.

Container Gardens: Usually these are planted in a soilless mix (lightweight potting soil). Use 20-30-20 Blossom Booster every 10 days especially for baskets that need frequent watering.

Trees and Shrubs: Use 20-20-20 All Purpose or 17-6-6 Acid Special once a month. Make an application early in the season timed with the typical growth spurt. Pin Oaks in particular thrive on the 17-6-6 Acid Special with its low pH, sulfur and available trace elements.

Houseplant Care: We recommend CLF (constant liquid feeding) for all types of indoor plant care. Dissolve ¼ teaspoon in an empty plastic gallon milk or water jug and use this solution each time your plants need watering.


Professional Growers: Helping you grow the highest quality plants with the most efficiency

Plants by pH

In the past, one standard fertilizer program served well to produce nearly all the plants in the greenhouse. Now, each new season finds growers facing the challenge of producing many different plants species and/or cultivars. While the introduction of new plants helps to stimulate sales, it presents special production challenges. These introductions have diverse cultural requirements. What works well to produce one cultivar may not work well for another.

Begin by Testing

Implementing a testing program is key to ensuring successful crops. An understanding of one’s water quality, proper fertilizer selection and nutritional monitoring are essential. Too often, growers wait until they see a problem before they fully consider these factors. The time and expense of a proper testing program is cheaper and less problematic than costly mistakes. Begin with a water test. This is the foundation for building a proper fertilizer program. Call for technical help and recommendations as needed. It is the growers’ responsibility to call for technical assistance and to review results.

Plant Species Groups

Plant species produced for spring sales vary greatly in their growing medium pH preferences. To best facilitate micronutrient management, group species by their growing medium pH. Most spring flowering plants can be placed in one of the three following categories. While the following lists are extensive, they are not complete. Be sure to refer to the cultural guidelines provided by plant suppliers.

LOW pH or PETUNIA GROUP

These plant materials grow best with a lower growing medium pH, approximately 5.4–5.8. They are prone to iron, boron, and other micronutrient deficiencies.

Acalypha- Chenille Plant

Bougainvillea

Nemesia

Snapdragon*

Alternanthera

Brachyscome

Osteospermum*

Sutera

Anagallis

Bracteantha*

Pansy

Thunbergia

Bacopa

Browallia

Petunia

Tiarella

Begonia-Dragon Wing

Calibrachoa

Phlox - Intensia

Torenia*

Begonia semperflorens

Diascia

Primula*

Verbena*

Begonia-Tuberous

Lantana*

Ranunculus

Vinca

Bidens*

Lobelia*

Scaevola

Zinnia

*This species has been listed in more than one group by various plant suppliers.

 

MODERATE pH or General Group

These plant materials grow best with a moderate growing medium pH, approximately 5.8–6.2. They are not particularly prone to micronutrient deficiencies or toxicities.

Angelonia

Dahlia

Mecardoia

Primula*

Ageratum

Euphorbia ‘Diamond Frost’

Melapodium

Rudbeckia

Argyranthemum

Fuchsia

Mimulus

Schlumbergera

Begonia

Gaura

Nicotiana

Salvia

Bidens*

Gazania

Oenothera

Sanvitalia

Bracteantha*

Gerbera

Osteospermum*

Schizianthus

Chrysanthemum

Impatiens*

Oxalis

Snapdragon*

Cineraria

Lantana*

Penstemon

Torenia*

Coleus

Lobelia*

Poinsettia

Verbena*

*This species has been listed in more than one group by various plant suppliers.

 

HIGH pH or Geranium Group

These plant materials grow best with a higher growing medium pH, approximately 6.2-6.8. They are prone to iron, manganese and other micronutrient toxicities.

Abutilon

Celosia

Heliotrope

New Guinea Impatiens

Alocasia

Cleome

Impatiens*

Pentas

Aloe

Cuphea

Ipomoea

Perilla

Anisodontea

Cyclamen

Iresine

Plectranthus

Arctotis

Dianthus*

Lisianthus  (Eustoma)

Portulaca

Begonia-Rex

Seed and Zonal Geraniums

Marigold

Salvia

Calendula

Helichrysum

Nierembergia

Sedum

 

 

Sun Patiens

Streptocarpus

*This species has been listed in more than one group by various plant suppliers.

 

Follow-up with Lab and In-House Growing Media Tests

A well-designed testing program uses weekly in-house testing of growing medium pH and soluble salts (E.C.) in conjunction with laboratory tests. This allows for correlation of in-house testing equipment with professional lab equipment so that growers can track their crops with the confidence that their testing measurements are understandable. A successful testing program is based on tracking one “model” or test crop (one species or cultivar) in one pot size all the way through the production cycle. Submit samples in a logical and timely manner that suits your production program. Be sure to sample the growing medium at the same interval following a fertilizer application. This will enable you to track the progress of your crop from one test to the other and allow you to proactively change the nutritional course of the crop before problems occur.

Most greenhouse operations produce numerous crops in a wide variety of container sizes. Choose one container size for the test crop. Do not mix growing medium samples from different size containers, even if they are from the same crop. In-house testing does not provide as much detail as lab test samples nor are they likely to result in the same numbers due to preparation and testing differences. However, the test numbers should follow the same general trend and provide valuable comparable data. Use test analyses in conjunction with cultural and environmental records from previous crops so that you can determine where changes may be needed. Prior records should indicate where growing methods or changes produced an exceptional crop so that you have a greater chance to reproduce those results. Additionally, there are wide regional differences in timing or environmental control that may affect the nutritional status of your crops.

Reproduced from GMPRO MAY 2006 by permission of Authors, K. Kackley, S. Ferry & C. Peters. (Updated 1/2011 C.Peters)

Water Quality

The Level of Alkalinity in the Water

A simple way to think of alkalinity is as the ability of your water to neutralize acid. The higher the alkalinity, the more acid it will take to lower the pH of your water. Alkalinity is composed of bicarbonates, carbonates and hydroxides joined to calcium, magnesium or sodium. These are the same components found in antacids, such as Tums or Rolaids, baking soda, limestone and lye. Alkalinity is expressed as ppm calcium carbonate equivalent. The higher the number, the more of these components there are in the water. Alkalinity levels are of more concern for crops grown in small containers and for those grown for a long period of time. Table 1 lists recommended alkalinity ranges for various container sizes.

Table 1.  JR Peters Laboratory Alkalinity Guidelines

 

RECOMMENDED RANGE

LEVEL OF CONCERN1

 

ppm=mg CaCO3/L

Milliequivalents2 CaCO3

ppm=mg CaCO3/L

Milliequivalents CaCO3

Plugs

60-100

1.2-2.0

<40, >120

<0.8, >2.4

Small pots/Shallow flats

80-120

1.6-2.4

<40, >140

<0.8, >2.8

4” to 5” pots/deep flats

100-140

2.0-2.8

<40, >160

<0.8, >3.2

Pots > 6”/long term crops

120-180

1.6-3.6

<60, >200

<1.2, >4.0

 

1 Alkalinity levels are intended as guidelines only and are dependant on the plant and media type, pot diameter/size, acidity of the feed program and watering practices. 

Milliequivalents=ppm total alkalinity expressed as mg CaCO3/liter divided by 50.

 

High alkalinity water may cause a gradual increase in the growing media pH.  As the pH climbs, availability of certain plant nutrients, particularly the micronutrients like iron and manganese are negatively affected resulting in deficiencies. It may be necessary to inject mineral acid (sulfuric or phosphoric) into the water or to use acidic media amendments, such as sulfur, or “acid-forming” fertilizers. To determine the amount of mineral acid you need to use to reduce the alkalinity of your water, access the alkalinity calculator located on the web on the North Carolina State University website at http://www.floricultureinfo.com/ and clicking on the floriculture software link. Do not use water that has been water softened. Water softeners add harmful sodium while removing desirable calcium and magnesium.  Water softeners do not reduce water alkalinity.

Low alkalinity water usually lacks the components that neutralize acid. As a consequence, the continued use of potentially acidic fertilizers, like many all-purpose formulas, may result in an undesirable decrease in the pH of the growing medium. As the pH drops, certain plant nutrients like iron and manganese may become available in toxic amounts. In addition, these waters are often deficient in calcium, magnesium or sulfate and additional supplements may be needed. A fertilizer program that alternates a potentially basic fertilizer containing calcium and magnesium with a low potential acidity fertilizer can help prevent pH crashes in the growing media and supply needed nutrients.

The Quality of your greenhouse water

Table 2.  JR Peters Laboratory Water Quality Guidelines

PARAMETERS

NORMAL RANGE

LOW

HIGH

 

Soluble Salts (mmhos/cm)

0.3 to 1.0

<0.2

>1.3

 

M

A

C

R

O

S

Nitrate Nitrogen (NO3-N)

-----

-----

>10

Ammonium Nitrogen (NH4-N)

-----

-----

>10

Phosphorus (P)

-----

-----

>10

Potassium (K)

-----

-----

>10

Calcium (Ca)

40 to 75

<25

>100

Magnesium (Mg)

30 to 50

<15

>50

Sulfur (S)

10 to 80

<10

>80

T

R

A

C

E

S

Manganese (Mn)

-----

-----

>1.50

Iron (Fe)

-----

-----

>2.00

Copper (Cu)

-----

-----

>0.20

Boron (B)*

-----

-----

>0.50

Zinc (Zn)

-----

-----

>0.40

Molybdenum (Mo)

-----

-----

>0.20

O

T

H

E

R

Sodium (Na)

-----

-----

>50

Chlorides (Cl)

-----

-----

>70

Fluorides (F)

-----

-----

>1.0

Aluminum (Al)

-----

-----

>1.0

 

*Poinsettias are sensitive to boron. A level equal to or greater than 0.25 ppm may be considered high and could cause toxicity.

Nitrogen, phosphorus, and potassium levels greater than 10 ppm may indicate contamination of the water source, possibly due to nutrient runoff; however, there is no negative effect on plant growth if these nutrients are present. 

High levels of trace elements and other elements, such as sodium and chloride, in irrigation water may result in plant toxicity. Consult with a water treatment specialist to determine the source of these elements and appropriate treatment methods.

References:

Biernbaum, J.A. 1994. Water quality. In Tayama, H.K., T.J. Roll and M.L. Gaston. Eds. Tips on growing bedding plants, 3rd ed., Ohio Flor. Assoc., Columbus, OH.

 

JR Peters Laboratory; Data complied from statistical analysis of testing results (1989-2006).

 

Finding your perfect match

Utilizing Your JR Peters Lab Results to Select the Proper Jack’s Professional® Fertilizers

Now that you have your water test results, you can begin the process of selecting the correct fertilizer to grow your crops. The first step in the process is to determine the nutritional needs of the plant material you are growing. Once you have this information, you are ready to interpret the results of your water test and begin the process of fertilizer selection. 

Step 1:  Begin by examining the level of alkalinity in the water.

A simple way to think of alkalinity is as the ability of your water to neutralize acid. The higher the alkalinity, the more acid it will take to lower the pH of your water. Alkalinity is composed of bicarbonates, carbonates and hydroxides joined to calcium, magnesium or sodium. These are the same components found in antacids, such as Tums or Rolaids, baking soda, limestone and lye. Alkalinity is expressed as ppm calcium carbonate equivalent.  The higher the number, the more of these components there are in the water. Alkalinity levels are of more concern for crops grown in small containers and for those grown for a long period. Table 1 lists recommended alkalinity ranges for various container sizes.

Table 1.  JR Peters Laboratory Alkalinity Guidelines

CONTAINER SIZE

RECOMMENDED RANGE

LEVEL OF CONCERN1

 

ppm=mg CaCO3/L

Milliequivalents2 CaCO3

ppm=mg CaCO3/L

Milliequivalents CaCO3

Plugs

60-100

1.2-2.0

<40, >120

<0.8, >2.4

Small pots/Shallow flats

80-120

1.6-2.4

<40, >140

<0.8, >2.8

4” to 5” pots/deep flats

100-140

2.0-2.8

<40, >160

<0.8, >3.2

Pots > 6”/long term crops

120-180

1.6-3.6

<60, >200

<1.2, >4.0

 

1 Alkalinity levels are intended as guidelines only and are dependent on the plant and media type, pot diameter/size, acidity of the feed program and watering practices. 

2 Milliequivalents=ppm total alkalinity expressed as mg CaCO3/liter divided by 50.

High alkalinity water may cause a gradual increase in the growing media pH. As the pH climbs, availability of certain plant nutrients, particularly the micronutrients like iron and manganese are negatively affected resulting in deficiencies. It may be necessary to inject mineral acid (sulfuric or phosphoric) into the water or to use acidic media amendments, such as sulfur, or “acid-forming” fertilizers. To determine the amount of mineral acid you need to use to reduce the alkalinity of your water, access the alkalinity calculator located on the web on the North Carolina State University website at http://www.floricultureinfo.com/ and clicking on the floriculture software link. Do not use water that has been water softened. Water softeners add harmful sodium while removing desirable calcium and magnesium. Water softeners do not reduce water alkalinity.

Low alkalinity water usually lacks the components that neutralize acid. As a consequence, the continued use of potentially acidic fertilizers, like many all-purpose formulas, may result in an undesirable decrease in the pH of the growing medium. As the pH drops, certain plant nutrients like iron and manganese may become available in toxic amounts. In addition, these waters are often deficient in calcium, magnesium or sulfate and additional supplements may be needed. A fertilizer program that alternates a potentially basic fertilizer containing calcium and magnesium with a low potential acidity fertilizer can help prevent pH crashes in the growing media and supply needed nutrients.

Step 2: Examine the level of nutrients that may present a concern.

Nutrient levels in water are expected to be low. The exceptions to this rule are calcium, magnesium and sulfur, which frequently occur naturally in water. The normal ranges of plant nutrients in water are listed in Table 2.

Table 2.  JR Peters  Laboratory  Water  Quality  Guidelines

PARAMETERS

NORMAL RANGE

LOW

HIGH

 

Soluble Salts (mmhos/cm)

0.3 to 1.0

<0.2

>1.3

 

M

A

C

R

O

S

Nitrate Nitrogen (NO3-N)

-----

-----

>10

Ammonium Nitrogen (NH4-N)

-----

-----

>10

Phosphorus (P)

-----

-----

>10

Potassium (K)

-----

-----

>10

Calcium (Ca)

40 to 75

<25

>100

Magnesium (Mg)

30 to 50

<15

>50

Sulfur (S)

10 to 80

<10

>80

T

R

A

C

E

S

Manganese (Mn)

-----

-----

>1.50

Iron (Fe)

-----

-----

>2.00

Copper (Cu)

-----

-----

>0.20

Boron (B)*

-----

-----

>0.50

Zinc (Zn)

-----

-----

>0.40

Molybdenum (Mo)

-----

-----

>0.20

O

T

H

E

R

Sodium (Na)

-----

-----

>50

Chlorides (Cl)

-----

-----

>70

Fluorides (F)

-----

-----

>1.0

Aluminum (Al)

-----

-----

>1.0

 

*Poinsettias are sensitive to boron. A level equal to or greater than 0.25 ppm may be considered high and could cause toxicity.

Nitrogen, phosphorus, and potassium levels greater than 10 ppm may indicate contamination of the water source, possibly due to nutrient runoff; however there is no negative effect on plant growth if these nutrients are present. 

High levels of trace elements and other elements, such as sodium and chloride, in irrigation water may result in plant toxicity. Consult with a water treatment specialist to determine the source of these elements and appropriate treatment methods.

Step 3:  Determine whether a calcium-containing fertilizer is needed.

Most all-purpose water soluble fertilizers do not contain calcium or magnesium but some water can serve as a source of these essential plant nutrients. If calcium is not supplied by the irrigation water, it is recommended that it be added by a water soluble fertilizer. Most greenhouse crops grow best when they are supplied with a minimum of 50-60 ppm calcium on a continuous basis. Herbaceous perennial and woody plant crops may grow well with slightly lower calcium levels. Poinsettias perform best when continuously supplied with 100-150 ppm calcium. Low calcium levels may be corrected by supplementing with a calcium-containing fertilizer such as Jack’s Professional 15-5-15, 13-2-13, 15-0-15, or 15-0-14

Sodium is an undesirable component of some waters. Sodium bicarbonate can raise the pH of the growing medium while supplying a potentially toxic element. The best way to minimize the negative effect of sodium in the water is to supply calcium at a level greater than or equal to that of sodium.

Step 4:  Check for imbalances and sulfur levels.

The ideal ratio of calcium to magnesium in water or fertilizer solutions is 2 parts calcium to1part magnesium (2:1). Acceptable ratios range from 5:1 to 1:1. Low magnesium levels can be corrected with a drench of Epsom salts (MgSO4 - magnesium sulfate) or by adding Epsom salts to non-calcium containing fertilizers. Sulfur is reported as elemental S. To convert to sulfate (SO4-), multiply by 3. Small amounts of sulfur can be added through the addition of Epsom salts (magnesium sulfate) to non-calcium fertilizer formulations. DO NOT MIX any sulfur-containing compounds with calcium, an insoluble precipitate will form.  One ounce of Epsom salts per 100 gallons of water will deliver 7.5 ppm Mg and 30 ppm SO4. The following Jack’s Professional fertilizers contain magnesium in addition to calcium: 15-5-15, 13-2-13, 15-0-14, or 15-4-15. If it is necessary to add more magnesium to a calcium-containing fertilizer, it is possible to add magnesium nitrate, 10-0-0.

Step 5:  Consider the nitrogen sources and potential acidity or basicity of the fertilizer.

Nitrogen can be supplied in fertilizers in three forms; nitrate (NO3-), ammonium (NH4+), or urea (CO(NH2)2).  The forms of nitrogen in a fertilizer product determine whether the tendency of a particular fertilizer is to raise the pH of the growing medium (potentially basic) or to lower the pH (potentially acidic). The potential acidity or basicity of a fertilizer product is referred to as its CCE (calcium carbonate equivalent) and it is expressed in pounds.  This value can be found on the label of the fertilizer. The higher the number, the more effect the fertilizer potentially has to change the pH of the growing medium. The absolute value of this number is not important, but it provides an indication of how strong an acidifier a product may be. High nitrate fertilizers are generally potentially basic while ammoniacal and urea-based fertilizers are generally potentially acidic. Use of a product with high potential acidity may help to prevent the need for mineral acids; however, the pH effect of the fertilizer is not the sole factor to consider when selecting a product.

Products high in the nitrate form of nitrogen tend to produce sturdier, stockier plants, while the ammoniacal and urea forms of nitrogen produce softer, more lush growth.  Another factor to consider is that under cool, wet conditions, fertilizers high in ammonium and urea may result in an accumulation of ammonium around plant roots and this may result in ammonium toxicity. For these reasons, many growers select fertilizers with at least 60% nitrate nitrogen for use in the greenhouse, especially during to cool, short days of early spring and when there is an extended period of cool, wet weather. During the high light and warm days of late spring, summer and early autumn, fertilizers with more ammonium and urea may be used.

Step 6:  Select fertilizer based on your water quality and crop needs.

After you have evaluated your results for the above factors it is time to select the fertilizer that best fits the needs of the crops you are growing. There is a large selection of fertilizers available that can be mixed and matched to fit your needs. Review the cultural guidelines provided by plant suppliers and modify them as needed based on your geographical and environmental factors.  Group plants with similar cultural requirements.  For further information of grouping plants, refer to the Jack’s Professional® Technical Bulletin Group Your Plants by Growing Medium pH Preference.

Table 4, below, provides an outline to follow for selecting a proper fertilizer for your water type. Remember, that these are general comments and that your crop may have specific requirements that may alter your selection. Some crop specific characteristics are listed here:

Table 3.  JR Peters Laboratory  General  Fertilizer  Selection  Guidelines

Crop

Specific Crop Requirements and Suggested Cultural Practices:

Jack’s Professional Crop

Specific Formulations

Plugs

Water alkalinity 75-100 ppm CaCO3, low phosphorus levels to control height and a high nitrate to ammonium nitrogen ratio.

13-2-13 LX Plug

16-2-15 LX  High Alkalinity Water Plug

Mums

 

pH 5.8 - 6.2, prone to iron deficiency if pH too high. Watch cultivar ‘Jessica’, it is one of the first to show high pH symptoms.

22-5-16 Mum FeED

 

Poinsettia

pH 5.8 - 6.2, low B, high Mo and Zn. Supply calcium at 90-100 ppm on a continuous basis. Dark-leafed cultivars require ~25% less fertilizer than traditional green cultivars. The current industry recommendations to feed at 200-250 ppm N can result in low micronutrient levels in media and tissue - MOST (micronutrient) applications are common. 

15-4-15 Poinsettia FeED Ca-Mg,

17-5-19 Poinsettia FeED plus Mg

Pansy, Vinca, Salvia, Snaps, Wax Begonia

pH < 6.0 for Fe/Mn availability, prefer nitrates in cool, wet conditions, and require additional B

15-2-20 Spring Pansy FeED

17-3-19 Fall Pansy FeED

Seed/Cutting Geraniums, African Marigold, Pentas

pH 6.2+ to avoid Fe/Mn toxicity, require additional B, and respond well to Mg or NH4+ for “green-up”.

15-15-15 Geranium

Petunia/Calibrachoa/Vegetative Annuals

pH < 6.0 for Fe/Mn availability, MOST (micronutrient) and/or iron applications common/mandatory. Jack’s Petunia FeED.

20-3-19 Petunia FeED

Jack’s Professional crop specific formulations are designed to fulfill all these requirements in a single product when applied with water of moderate alkalinity.
Selecting Fertilizers Based on Water Quality:

Table 4.  JR Peters  Laboratory  General  Fertilizer  Selection  Guidelines

Alkalinity Levels In ppm CaCO3

Characteristics to Consider

Jack’s Professional® Fertilizer Suggestions

Less than 60 ppm-

Very Low Alkalinity

  • Closely monitor growing medium pH since it is easily influenced by fertilizer use and subject to drop with continual use of “all-purpose” formulas.
  • Very little calcium or magnesium is supplied by the water. Most plants require 40-60 ppm calcium on a continuous basis for best growth. Check your crops’ requirements and supplement as needed. 
  • Select fertilizers that are neutral or nearly neutral in their pH reaction or alternate potentially basic fertilizers with potentially acidic ones.
  • 17-4-17 LX Pure Water
  • 15-5-15 LX Calcium-Magnesium
  • 15-4-15 Poinsettia FeED Ca-Mg
  • 13-2-13 LX Plug
  • 15-2-20 LX Pansy, Vinca, Salvia
  • 20-10-20 PL + Mg alternate with 15-0-15
  • 15-16-17 PL + Mg alternate with 15-0-15
  • 15-5-25 alternate with 15-0-15 every third or fourth irrigation

60-100 ppm

Low Alkalinity

  • This is an ideal alkalinity for plug and small container production since it provides some pH buffering but is unlikely to cause an undesirable rise in media pH.
  • Compare calcium and magnesium levels with your crops’ requirements and supplement when necessary.
  • Select fertilizers that are neutral in their pH reaction or ones with low to moderate acidity.  Monitor growing medium pH frequently. 
  • Applications of potentially basic fertilizers may be needed to stabilize pH or to supply additional calcium.
  • 17-4-17 LX Pure Water
  • 15-5-15 LX Calcium-Magnesium
  • 15-4-15 Poinsettia FeED Ca-Mg
  • 15-2-20 LX Pansy, Vinca, Salvia
  • 13-2-13 LX Plug
  • 16-2-15 LX  High Alkalinity Water Plug
  • 20-10-20 PL (+  Mg if needed)
  • 20-3-19 Petunia FeED
  • 22-5-16 Mum FeED
  • 17-3-19 Fall Pansy FeED

100-180 ppm

Moderate Alkalinity

  • Compare the levels and balance of calcium, magnesium and sodium in the water.  Supplemental calcium may be needed and supplemental magnesium is most likely needed.
  • Select fertilizers with higher potential acidity.  Acid injection is unlikely to be needed with proper fertilizer selection. Acid injection may be needed if low acidity fertilizers are used.
  • Long-term crops and small containers MAY see a significant growing medium pH rise if water-soluble fertilizer rates are low.
  • 20-10-20 PL (+  Mg if needed)
  • 21-5-20 LX (+  Mg if needed)
  • 16-2-15 LX  High Alkalinity Water Plug
  • 20-3-19 Petunia FeED
  • 15-4-15 Poinsettia FeED Ca-Mg
  • 17-5-19 Poinsettia FeED with Mg
  • 22-5-16 Mum FeED
  • 17-3-19 Fall Pansy FeED

 

180-240 ppm

High Alkalinity

  • Calcium is usually adequate but magnesium is often low. Watch the sodium levels.
  • Growers desiring low acidity or “plug formulas” will probably need to inject acid.
  • Monitor the growing medium pH for low pH loving plants.
  • Low leach watering increases problems pH and soluble salts problems.
  • Note: Depending on fertilizer rate and medium pH, acid injection will most likely be necessary.
  • 21-5-20 LX+  Mg
  • 16-2-15 LX  High Alkalinity Water Plug
  • 20-3-19 Petunia FeED
  • 17-5-19 Poinsettia FeED with Mg
  • 22-5-16 Mum FeED
  • 17-3-19 Fall Pansy FeED
  • 21-7-7 Acid Special effective if media is well drained and warm and the crop is tolerant.

Greater than 240 ppm

Very High Alkalinity

  • These waters are often high in calcium, low in magnesium and may contain excessive sodium.
  • Acid injection will be required in most cases. 
  • Media pH rise almost certain in long-term crops or small containers.
  • Soluble salt build-up can be a problem.
  • 21-5-20 LX+  Mg
  • 16-2-15 LX  High Alkalinity Water Plug
  • 20-3-19 Petunia FeED
  • 17-5-19 Poinsettia FeED with Mg
  • 22-5-16 Mum FeED
  • 17-3-19 Fall Pansy FeED
  • 21-7-7 Acid Special effective if media is well-drained and warm and the crop is tolerant

Controlled Environment: Growing hydroponically with Jack’s

General Hydroponic growing with 2 part

Jack’s Professional Hydroponic Formula has been designed to serve as a base foundation for hydroponic growing. It can be manipulated in such a manner as to provide virtually any combination of nutrient levels desired, providing the highest availability to plants, due primarily to Jack’s proven ability to remain in true solution over long periods of time.

Jack’s Professional 5-12-26 Hydroponic

Follow these steps to obtain a precipitate free solution

  1. Dissolve 130 ounces of 5-12-26 Hydroponic in 1000 gallons of final feed solution. You will obtain the following elemental PPM concentrations:
    ElementNPKMgSO4FeMnZnCuBMo
    PPM5052215632463.50.15.15.50.10

    For the most effective use of the Hydroponic formula, it is essential that the nutrient content of the irrigation water being used is known. These figures are then taken into consideration and should be added to the distilled water figures as quotes above. This is of special importance when figuring the need for adding more Magnesium (Mg) and Calcium (ca) depending on the needs of the crops being grown.

  2. Dissolve any additional Epsom salts desired into the above 1000-gallon solution before proceeding. For most crops, 50 PPM Magnesium is an adequate level in solution. To increase your Magnesium levels, dissolve 10 ounces of Epsom salts in 1000-gallons of final feed solution to obtain 7.5 PPM additional Magnesium and 3.00 ppm Sulfur (SO4).


    IT IS ESSENTIAL THAT ANY EPSOM SALTS TO BE ADDED MUST BE ADDED TO THE HYDROPONIC SOLUTION AND BE DISSOLVED BEFORE THE ADDITION OF CALCIUM NITRATE.

    NOTE: Jack’s Hydroponic fertilizer contains NO calcium.

    After dissolving Jack’s Hydroponic and any Epsom salts in the tank, proceed as follows:

  3. Dissolve 86 ounces of Calcium Nitrate into the above 1000-gallon solution to obtain a total nutrient concentration of 150 PPM Nitrogen and 116 PPM Calcium.

    Should higher Nitrogen and Potassium levels be desired, the addition of 1-ounce Potassium Nitrate per 1000 gallons will add the following concentrations:

    Nitrogen—1.00 ppm NPotassium 2.74 ppm K

    Should higher Calcium levels be desired, the addition of 1 ounce Calcium Chloride per 1000-gallons would add the following concentrations:

    Calcium as Ca—2.09 ppm Ca

    Should higher Potash levels be desired, the addition of 1 ounce Potassium Sulfate per 1000-gallons would add the following concentrations:

    Potassium as K—3.11 ppm K

    Should higher Manganese levels be desired, the addition of 1-ounce Manganese sulfate per 1000 gallons would add the following concentrations:

    Manganese as Mn—1.87 ppm Mn

    Should higher Iron levels be desired, the addition of 1 ounce of the following per 1000 gallons will add the following concentrations:

    13% Chelated Iron as Fe EDTA — 0.975 ppm Fe
    11% Chelated Iron as Fe DTPA — 0.80 ppm Fe
    6% Chelated Iron as Fe EDDHA — 0.45 ppm Fe

    Jack’s Hydroponic Formula is heavily buffered to produce an idea working solution pH of between 6.00 and 6.50, but under unusual circumstances, it may be necessary to adjust the solution pH up or down with the use of mineral or organic acid complexes. Please consult water quality when choosing amount for pH change.

    For over 65 years, the Peters’ family has designed and produced "The Finest in Soluble Fertilizers"

    Our laboratory has been providing outstanding analytical services to the horticulture industry for over 55 years. Professional growers, horticultural products manufacturers, and university researchers throughout the world trust us to supply accurate and timely services.


Copyright 2016 JR Peters Inc.