After the busy Spring season, it’s time to focus on preparing for Fall garden mums. These plants are an important source of seasonal revenue for many growers. However, the production cycle presents several challenges, including high temperatures, pest and disease pressure, managing fertility and irrigation, and crown budding. This article will address the common issues mum growers encounter and provide practical solutions to overcome them.
pH & Fertility
Ensuring adequate fertility throughout the mum production cycle is crucial for successful growth and meeting plant size requirements. Garden mums are heavy feeders, and insufficient nutrition at any stage can compromise crop quality.
Managing water quality is essential for maintaining proper fertility in mum crops. It’s recommended to conduct a comprehensive horticultural laboratory water test every two years. Based on the results, GGSPro can provide recommendations on fertilizer choice and acid injection if necessary. The ideal pH for garden mums is between 5.4 and 5.8, which can often be maintained using acid forming fertilizers. If only controlled-release fertilizers (CRF) are used, acid injection might be needed if the irrigation water has high alkalinity.
Fertility for garden mums can be managed using controlled-release fertilizer (CRF), water-soluble fertilizer (WSF), or a combination of both, known as the “Half and Half” approach by GGSPro (Figure 1). Overhead irrigation growers often find CRF programs more efficient, while drip irrigation growers typically prefer WSF. The Half and Half approach offers flexibility in adjusting the fertility program and provides protection against nutrient leaching from heavy rain events, as CRF supplies a constant nutrient source. Using CRF requires WSF during the initial two weeks to meet the crop’s heavy nutritional needs and promote soft growth for maximum branching.
Figure 1: Recommended fertility programs for garden mum production.
Mums have a high demand for iron and prefer a low pH of 5.4-5.8. As pH rises, iron availability decreases, causing deficiency symptoms like yellowing at the growing tips while veins remain green (Figure 2). Different mum varieties show iron deficiency at varying thresholds, so the problem may start in a few more sensitive varieties and spread. Iron deficiencies are a leading cause for uniformity issues within a mum crop.
To prevent or correct iron deficiency in the long-term, adjust the pH to the ideal range. GGSPro can help with this by suggesting sulfuric acid injection or acid fertilizers. Even after pH correction, applying chelated iron might be necessary. Use Sprint 138 or 330 as a drench at 4-5 oz per 100 gallons. Avoid foliar sprays or dry soil treatments to reduce the risk of phytotoxicity. Do not apply chelated iron to water-stressed plants, and always rinse the foliage after application to prevent pitting burns from dried iron solution.
Figure 2: Mum foliage showing iron deficiency.
Mums also benefit from additional magnesium, which can be provided with Epsom salts. For continuous application, use 2 oz of Epsom salts per 100 gallons along with your non-calcium-based fertilizer. Alternatively, apply 8 oz per 100 gallons biweekly or as needed. Magnesium deficiency is shown as interveinal chlorosis on the lower leaves.
Though mums are heavy feeders, they can still suffer from high soluble salts damage, often caused by drought or applying fertilizer to dry media. These conditions lead to a high concentration of fertilizer salts around the roots. To prevent this, avoid drought stress and always apply fertilizer to slightly moist media.
Premature Budding (Crown Budding)
As breeders continue to enhance mums with improved traits like better branching, increased blooms, and unique colors and forms, some newer cultivars show less pronounced photoperiod responses compared to older varieties. This has led to a higher incidence of premature or crown budding, which occurs in response to moderate temperatures and shorter day lengths. However, issues like water stress and low fertility can worsen this problem. Early detection allows for effective recovery from premature budding. For crops treated with hand pinching or Florel, recovery strategies are similar to those used in the No Pinch method: increase feeding to 300-400 ppm for 7-10 days and ensure adequate moisture levels. If needed, high phosphorus containing fertilizer such as 20-10-20 or 20-20-20 fertilizer is recommended for recovery to push lower growth past the existing crown buds. Applying Florel at 750 ppm 7 days apart for 3 weeks, if within your bloom schedule, can combat premature buds, which often open up under new vegetative growth and do not affect final quality. Shearing premature buds is labor-intensive and typically does not improve quality, so it’s generally not advised. If left unaddressed, premature budding can lead to undersized flowers blooming too early and undersized plants (Figure 3). Growers should regularly monitor crops to identify premature budding from late spring through early July. Please note that the general cut-off date for Florel is July 4th to avoid bloom delay.
Figure 3: Severe crown budding on mum.
Pests & Diseases
Common pests such as aphids, caterpillars, leafminers, mites, thrips, and whiteflies pose significant challenges to garden mums. Occasionally, broad and cyclamen mites can also cause severe damage to mum crops. It’s crucial to minimize pesticide exposure to bees. Avoid using upwardly mobile drench products within 5-6 weeks of flowering and opt for spray products with reduced bee exposure risk. Stop using products with residual risk at least two weeks before flowering and apply pesticides in the evening after bee foraging has ceased. Contact GGSPro for recommended products and strategies to effectively manage insect and mite pests while safeguarding pollinators.
Growers should also be aware of common root and crown diseases in garden mums. Pythium and Fusarium are the most prevalent root and crown diseases affecting mums, particularly Pythium aphanidermatum in hot weather (Figure 4). Early preventative treatments after planting are recommended to combat both diseases. Rhizoctonia can cause web blight near the soil line and requires different chemical treatments.
Figure 4: Pythium attacking the roots causing wilt of foliage.
Moving beyond root and crown diseases, growers should also monitor for foliar diseases in garden mums. Certain varieties may exhibit higher susceptibility to these diseases, so maintaining detailed records and removing susceptible varieties from cultivation can help manage issues effectively. Botrytis and various leaf spots are common threats to foliage, with bacterial leaf spot posing a particularly serious challenge during certain growing seasons. The bacteria Pseudomonas spreads easily through splashing water from rain or overhead irrigation and is difficult to eradicate with chemical methods. Copper, Mancozeb, and Quaternary ammonium products are essential preventive tools upon detecting signs or symptoms of bacterial disease during scouting.
In conclusion, the successful cultivation of Fall garden mums requires a comprehensive approach to overcome various challenges throughout the production cycle. With careful attention to the factors discussed in this article, growers can avoid the most common issues experienced in mum production and maximize their return on investment.
Here are various “staple” products to consider investing in when growing mums:
* Other sizes available
Note, not all products are registered in all states. Some pesticides are restricted use in some states or regions and not others. It is the responsibility of the applicator to read and follow all label directions, remembering that labels may change. Other products may be safe and effective. Rates, application methods, and edible status are detailed in our GGSPro Insecticide & Fungicide Guides. Griffin also offers the 5th Edition GGSPro Technical Reference Guide in both English and now Spanish versions. This valuable resource outlines a wide range of pest control options and information on pollinator safety, BCA’s, scouting, weed management, plant lighting, nutrition, water quality and more!
pH & Fertility
Ensuring adequate fertility throughout the mum production cycle is crucial for successful growth and meeting plant size requirements. Garden mums are heavy feeders, and insufficient nutrition at any stage can compromise crop quality.
Managing water quality is essential for maintaining proper fertility in mum crops. It’s recommended to conduct a comprehensive horticultural laboratory water test every two years. Based on the results, GGSPro can provide recommendations on fertilizer choice and acid injection if necessary. The ideal pH for garden mums is between 5.4 and 5.8, which can often be maintained using acid forming fertilizers. If only controlled-release fertilizers (CRF) are used, acid injection might be needed if the irrigation water has high alkalinity.
Fertility for garden mums can be managed using controlled-release fertilizer (CRF), water-soluble fertilizer (WSF), or a combination of both, known as the “Half and Half” approach by GGSPro (Figure 1). Overhead irrigation growers often find CRF programs more efficient, while drip irrigation growers typically prefer WSF. The Half and Half approach offers flexibility in adjusting the fertility program and provides protection against nutrient leaching from heavy rain events, as CRF supplies a constant nutrient source. Using CRF requires WSF during the initial two weeks to meet the crop’s heavy nutritional needs and promote soft growth for maximum branching.
Figure 1: Recommended fertility programs for garden mum production.
Mums have a high demand for iron and prefer a low pH of 5.4-5.8. As pH rises, iron availability decreases, causing deficiency symptoms like yellowing at the growing tips while veins remain green (Figure 2). Different mum varieties show iron deficiency at varying thresholds, so the problem may start in a few more sensitive varieties and spread. Iron deficiencies are a leading cause for uniformity issues within a mum crop.
To prevent or correct iron deficiency in the long-term, adjust the pH to the ideal range. GGSPro can help with this by suggesting sulfuric acid injection or acid fertilizers. Even after pH correction, applying chelated iron might be necessary. Use Sprint 138 or 330 as a drench at 4-5 oz per 100 gallons. Avoid foliar sprays or dry soil treatments to reduce the risk of phytotoxicity. Do not apply chelated iron to water-stressed plants, and always rinse the foliage after application to prevent pitting burns from dried iron solution.
Figure 2: Mum foliage showing iron deficiency.
Mums also benefit from additional magnesium, which can be provided with Epsom salts. For continuous application, use 2 oz of Epsom salts per 100 gallons along with your non-calcium-based fertilizer. Alternatively, apply 8 oz per 100 gallons biweekly or as needed. Magnesium deficiency is shown as interveinal chlorosis on the lower leaves.
Though mums are heavy feeders, they can still suffer from high soluble salts damage, often caused by drought or applying fertilizer to dry media. These conditions lead to a high concentration of fertilizer salts around the roots. To prevent this, avoid drought stress and always apply fertilizer to slightly moist media.
Premature Budding (Crown Budding)
As breeders continue to enhance mums with improved traits like better branching, increased blooms, and unique colors and forms, some newer cultivars show less pronounced photoperiod responses compared to older varieties. This has led to a higher incidence of premature or crown budding, which occurs in response to moderate temperatures and shorter day lengths. However, issues like water stress and low fertility can worsen this problem. Early detection allows for effective recovery from premature budding. For crops treated with hand pinching or Florel, recovery strategies are similar to those used in the No Pinch method: increase feeding to 300-400 ppm for 7-10 days and ensure adequate moisture levels. If needed, high phosphorus containing fertilizer such as 20-10-20 or 20-20-20 fertilizer is recommended for recovery to push lower growth past the existing crown buds. Applying Florel at 750 ppm 7 days apart for 3 weeks, if within your bloom schedule, can combat premature buds, which often open up under new vegetative growth and do not affect final quality. Shearing premature buds is labor-intensive and typically does not improve quality, so it’s generally not advised. If left unaddressed, premature budding can lead to undersized flowers blooming too early and undersized plants (Figure 3). Growers should regularly monitor crops to identify premature budding from late spring through early July. Please note that the general cut-off date for Florel is July 4th to avoid bloom delay.
Figure 3: Severe crown budding on mum.
Pests & Diseases
Common pests such as aphids, caterpillars, leafminers, mites, thrips, and whiteflies pose significant challenges to garden mums. Occasionally, broad and cyclamen mites can also cause severe damage to mum crops. It’s crucial to minimize pesticide exposure to bees. Avoid using upwardly mobile drench products within 5-6 weeks of flowering and opt for spray products with reduced bee exposure risk. Stop using products with residual risk at least two weeks before flowering and apply pesticides in the evening after bee foraging has ceased. Contact GGSPro for recommended products and strategies to effectively manage insect and mite pests while safeguarding pollinators.
Growers should also be aware of common root and crown diseases in garden mums. Pythium and Fusarium are the most prevalent root and crown diseases affecting mums, particularly Pythium aphanidermatum in hot weather (Figure 4). Early preventative treatments after planting are recommended to combat both diseases. Rhizoctonia can cause web blight near the soil line and requires different chemical treatments.
Figure 4: Pythium attacking the roots causing wilt of foliage.
Moving beyond root and crown diseases, growers should also monitor for foliar diseases in garden mums. Certain varieties may exhibit higher susceptibility to these diseases, so maintaining detailed records and removing susceptible varieties from cultivation can help manage issues effectively. Botrytis and various leaf spots are common threats to foliage, with bacterial leaf spot posing a particularly serious challenge during certain growing seasons. The bacteria Pseudomonas spreads easily through splashing water from rain or overhead irrigation and is difficult to eradicate with chemical methods. Copper, Mancozeb, and Quaternary ammonium products are essential preventive tools upon detecting signs or symptoms of bacterial disease during scouting.
In conclusion, the successful cultivation of Fall garden mums requires a comprehensive approach to overcome various challenges throughout the production cycle. With careful attention to the factors discussed in this article, growers can avoid the most common issues experienced in mum production and maximize their return on investment.
Here are various “staple” products to consider investing in when growing mums:
| Item Name | MOA | Item Number | Size |
|---|---|---|---|
| 3336 F | 1 | 71-2575 | 1 qt.* |
| Banrot 40 WP | 1+14 | 71-1210 | 2 lb. |
| Cease | BM02 | 71-13301 | 1 gal.* |
| Fenstop | 11 | 71-14800 | 1 qt. |
| Heritage WG | 11 | 71-1400 | 1 lb.* |
| Medallion WDG | 12 | 71-16502 | 8 oz. |
| Mural WG | 7+11 | 71-1690 | 1 lb. |
| Orkestra Intrinsic | 7+11 | 71-2200 | 16 fl. oz.* |
| Postiva | 3 & 7 | 71-2400 | 28 fl. oz. |
| RootShield Plus WP | BM02 | 71-27951 | 1 lb.* |
| Segway O | 21 | 71-31102 | 16 fl. oz.* |
| Altus | 4D | 70-1161 | 64 fl. oz. |
| Conserve SC | 5 | 70-1365 | 1 qt. |
| DiPel Pro DF | 11A | 70-1450 | 1 lb. |
| Endeavor WP | 9B | 70-1655 | 15fl. oz. |
| Kontos | 23 | 70-19301 | 250 ml. |
| Mainspring GNL | 28 | 70-2331 | 1 pt.* |
| Pradia | 28+29 | 70-2630 | 1 qt. |
| Rycar | 9B | 70-2900 | 8 fl. oz. |
| XXpire | 4C+5 | 70-9700 | 1 lb. |
| Epsom Salt | 33-79160 | 25 lb. | |
| Sprint 330 | 67-70361 | 5 lb.* | |
| Sprint 138 | 67-70371 | 5 lb. | |
| Bonzi | 70-1260 | 1 qt.* | |
| Florel | 73-16551 | 1 qt.* | |
* Other sizes available
Note, not all products are registered in all states. Some pesticides are restricted use in some states or regions and not others. It is the responsibility of the applicator to read and follow all label directions, remembering that labels may change. Other products may be safe and effective. Rates, application methods, and edible status are detailed in our GGSPro Insecticide & Fungicide Guides. Griffin also offers the 5th Edition GGSPro Technical Reference Guide in both English and now Spanish versions. This valuable resource outlines a wide range of pest control options and information on pollinator safety, BCA’s, scouting, weed management, plant lighting, nutrition, water quality and more!