Mums thrive in hot weather with a lot of sun, food, and water.  This section covers how to grow your mums successfully the very first year.

Planting

Our plants arrive in early June.  By that time we have the plot laid out, geotextile in place, and the watering network completely set up.  Try to plant within a few days of receiving cuttings.  If they are not planted soon after receiving, they can begin to harden off and lose their ability to branch and grow as they should. 

The mum plugs are removed from the individual pockets and planted at the same level as the top of the plug.  Pack the medium around the plug tightly but not solidly. 

Watering

In mum production, it is important to maintain moderate to high growing media moisture. Allow the growing media to cycle from moist to slightly dry.  Avoid both excess dry downs and prolonged periods of wet media, especially in poor weather conditions, as this increases potential for root disease.

To prevent water spotting or burning on sunny days, it is best to water earlier in the morning or later in the afternoon.  We water first thing in the morning to prepare the plants for a good strong day of growing with food and water.

Watering with a drip irrigation system rather than overhead sprinklers can cause foliar diseases, especially later in the crop when a heavier canopy of foliage exists.  We only water with our drip irrigation system.

We always add fertilizer to our water when we water.  When the plants start out they are watered every other day or every third day.  We watch for water leaching out of the bottom of the pans as an indication of how wet the medium has become.  The system delivers 2 gallons of water to 4 plants every hour.  Generally 30 minutes is required for each section.  Therefore, 1,000 plants will receive 250 gallons of water per day, and watering takes 60 minutes.

Fertilizer Explained

Plants need significant amounts of nitrogen, phosphorus, and potassium to grow and thrive.  Well-fed plants are healthier and more productive.  Fertilizer is sold based on the NPK concentration.  Understanding the NPK ratios of fertilizers can help you choose the best combination for the type of plants you’re growing.

The N in NPK is nitrogen

Nitrogen helps plants make the proteins they need to produce new tissues – especially leafy tissues.  When plants don’t get enough nitrogen, they can turn yellow or pale green.  But on the flip side, if you give a plant too much nitrogen, it may grow tons of foliage but not produce flowers.

The P in NPK is phosphorus

Phosphorus stimulates root growth, helps plants set buds and flowers, and produce seeds.  It also helps plants use other nutrients more efficiently, and helps turn energy from the sun into usable energy for your plants.

The K in NPK is potassium

Potassium promotes the overall vigor of plants.  It helps the plants make carbohydrates and promotes disease resistance.  It also helps regulate metabolic activities.  Plants low in potassium may be stunted and have lower quantities of flowers.

Feeding

We feed our mums in two ways.  The first is passive feeding.  We add a slow-release fertilizer to the soil medium to provide food to the plants if we run into a wet period and can’t water the mums.  We also add the slow-release fertilizer for the end user.  This ensures the plants still have some food when they go home and our end customers are pleased with the longevity and look of our mums and want plants next year.

The daily feeding of mums is divided into three timed phases.  Phase 1 is the vegetative development phase.  This is roughly the first half of the growing season.  Mums are heavy feeders.  Lack of fertility during this phase will adversely affect plant size and quality.  During this phase we use Jack’s 20-10-20.  The recommended feeding rate for mums is 200-350 ppm of nitrogen.  We fertilize at a rate of 300 ppm throughout the first phase.

During Phase 2 (the flowering phase) nutrient demand drops and fertility can be reduced.  During this phase we use Jack’s 15-10-30.  We fertilize at a rate of 250 ppm during this phase.

Phase 3 is the final phase prior to sale.  This is the last three weeks of the growing season.  We reduce the feed rate to 50 ppm to harden the plants to allow them to ship better and last longer.

Stock Solution

Our system is set up to use a water-soluble fertilizer and inject the solution into the water going to the plants.  The fertilizers we chose are very hydroscopic and will begin to clump with the exposure to humidity in the air.  We try to keep the bag sealed and inside a bucket.  To feed our mums, we prepare a concentrated stock solution in a 5-gallon bucket and then dilute that through the fertilizer injector to the concentration we desire.

Fertilizer stock solutions are mixed according to the fertilizer injector ratio: each injector will deliver a certain amount of stock solution for each increment of irrigation water that passes through the injector.  For example, a 1:100 injector (which is what we use) will deliver 100 gallons of dilute fertilizer solution for each gallon of concentrated stock solution.  A 1:200 injector will deliver 200 gallons of dilute fertilizer for each gallon of concentrated stock solution (or 100 gallons of dilute solution per ½ gallon of stock).  If both injectors were to deliver 200 ppm of nitrogen from the same fertilizer, the stock solution for the 1:200 injector would have to be twice as concentrated as the one for the 1:100 injector.  Thus, the injector ratio determines the concentration of the stock solution that is needed to deliver a particular rate of fertilization.

The preparation of fertilizer stock solutions is of paramount importance.  You must accurately determine the amount of fertilizer needed to mix stock solutions of fertilizers.  Most of the manufacturers of commercial fertilizers and fertilizer injectors have produced tables that simplify this task.  Information is also provided on fertilizer bags.  Without recourse to tables or bags, you can use formulas to calculate the amount of fertilizer needed.  

The amount of fertilizer added to make the stock solution for Phase 1 is calculated as follows.

Given is this formula for calculating the fertilizer component:

The variables for this formula are:

Amount of fertilizer to add – This the weight of the fertilizer to add to the 5-gallon bucket for each gallon of water.

Desired concentration – The feeding rate desired.  The concentration is expressed in parts per million (ppm).

Dilution factor – The ratio setting being used on the fertilizer injector.  Our injector is a 1:100 ratio injector.

Percent of element in fertilizer – The nitrogen number from the NPK value on the bag.

Constant – The conversion factor to make all of the units work out correctly.  We use 75 as the constant to convert ounces to U.S. gallons.

Phase 1 Stock Solution calculations

Given:

• Concentration for heavy feeding (in ppm) = 300
• Dilution factor for our 1:100 injector =100
• Percentage of nitrogen in 20-10-20 fertilizer = 20
• Constant to convert ounces to gallons = 75

Amount = 20 ounces of 20-10-20 fertilizer per 1 gallon of water

The results of the calculations match up with the instructions on the back of our fertilizer bag.  By adding the values in the 1:100 column for 100 ppm (6.75) and the value for 200 ppm (13.5) together, you get very close to the same results: 20.25 ounces per 1 gallon of water.

Phase 2 Stock Solution calculations

Given:

• Concentration for flowering (in ppm) = 250
• Dilution factor for our 1:100 injector =100
• Percentage of nitrogen in 15-10-30 fertilizer = 15
• Constant to convert ounces to gallons = 75

Amount = 22 ounces of 15-10-30 fertilizer per 1 gallon of water

Phase 3 Stock Solution calculations

Given:

• Concentration for hardening(in ppm) = 50
• Dilution factor for our 1:100 injector =100
• Percentage of nitrogen in 15-10-30 fertilizer = 15
• Constant to convert ounces to gallons = 75

Amount = 4 ounces of 15-10-30 fertilizer per 1 gallon of water

Testing

During the day-to-day operation of the mum garden, the actual delivered concentration of the fertilizer being delivered must be monitored.  The method usually used is electrical conductivity or E.C.  EC is measured by the use of an Electrical Conductivity meter.  The value from the EC meter is a measure of the Total Dissolved Solids (TDS) in the liquid.

Electrical Conductivity Meter

To perform the test, take a measurement of the water fed to the fertilizer injector (tap water).  This will identify any TDS in the water.  Then collect liquid after the injector and measure the total EC.  Subtract the baseline reading from the final reading and that is the EC added by the fertilizer.  To convert the Electrical Conductivity (EC) reading to parts per million (ppm), simply multiply the results times 156.25.  For our three examples above, the readings should be as follows:

EC Reading of water after the injector (fertilizer added)
EC reading before the injector (no fertilizer)
Difference in EC readings
Desired reading for 300 ppm (Calculation 1)	1.92
Desired reading for 250 ppm (Calculation 2)	1.60
Desired reading for 50 ppm (Calculation 3)	0.32

Disease Treatment

Fungus is the biggest problem we have experienced.  Waiting until the fungus shows up is too late, so we apply a fungicide every four weeks.  Since our medium is soilless, we do not start out with a treatment.  The same fungicide cannot be used back to back, so we use three different types; Banrot 40P, Mural, and Medallion.  The fungicide is added to the normal watering schedule on the designated date.  The application rates are based on the surface area of all of the plants.  The total surface area of 1,000 pans is calculated as follows.

• The pans are 9” at the top. 
• The area of each pan is =(4.5”/12”per ft) * (4.5”/12” per ft) * pi = 0.4418 sq ft.
• For 1,000 plants; 1,000 * 0.4418 = 441.8 sq ft

The directions on the Banrot label indicate an application rate of 8-12 ounces per 400 square feet of coverage. 

• Using 10 ounces; 441.8 sq ft /400 sq ft per 10 ounces = 11.045 ounces

Mural fungicide has an application rate of 2 to 3.5 oz. of product per 5,000 sq ft.  The fungicide should be diluted into a minimum of 50 gallons of water which is less than a normal watering.

• Using 3.0 ounces; 441.8 sq ft/5,000 sq ft per 3.0 ounces = 0.27 ounces

Medallion WDG fungicide is the final fungicidal application.  The application rate is a maximum of 1.5 oz per 1,000 sq ft per year. 

• Using 1.5 ounces; 441.8 sq ft/1,000 sq ft per 1.5 ounces = 0.667 ounces

Although the individual dosing of fungicide are not significantly expensive, the purchase price of one of the smallest container of each is over $500.

Feeding Schedule

Pests

Mums are not a desirable food source for most garden/farm pests (rodents, deer, rabbits, etc.).  Our experience has shown that rats have posed the most serious damage by chewing water hoses during extremely dry periods.  Bait traps could help, but we have not used any of these.