Guarding Garden Mums

The production of garden mums during the summer months does not come without challenges. A large percentage of mums are produced outside where they are subject to varying weather conditions, along with insect and disease pressure. Being prepared for the potential challenges ahead can help you avoid losses and ensure plant quality for successful fall sales.

Common pests

Aphids found feeding on the underside of leaves
In all stages of production, garden mums can be susceptible to:
  • Aphids
    • Aphid populations can grow very quickly due to their fast development time in warmer months. They can be found feeding in groups on new growth, stems, buds and even lower leaves. Feeding will cause leaves to curl, distort and lighten in color. In addition, aphids can spread Chrysanthemum Virus B, so early detection and control is key.
  • Thrips
    • Thrips can be difficult to control because of their high reproductive rate and short life cycle. They tend to pose a higher threat once mums have bloomed, but injury to foliage can still occur earlier in production. Watch out for leaf stippling and distortion, as well as discolored and rolled terminals. Thrips also act as a vector for Impatiens Necrotic Spot Virus and Tomato Spotted Wilt Virus, which can spread rapidly throughout mums and other crops.
  • Worms
    • Loopers, armyworms and other lepidopteran pests can do quite a bit of damage if not found in time. Be observant for moth activity in the production area so appropriate controls can be applied to stop them before they get a chance to feed on terminals.
Common diseases

The primary disease problems encountered during mum production are root rots, caused by Pythium spp., and Fusarium wilt, caused by Fusarium oxysporum. High temperatures and direct sunlight on mum containers can raise soil temperatures and cause stress to the root system.

Pythium spp. infections tend to occur more in southern regions. Soil that contains high soluble salts can lead to root burn, making plants more susceptible to infections. This pathogen can spread to neighboring plants through water movement, so it is important to elevate pots in low areas where water may pool. Symptoms to watch for are wilting and light green/yellowing leaves.

Fusarium wilt is more common when plants are stressed. The pathogen typically invades one side of the vascular system, which results in signs of one-sided wilt. Infections will also make sections of the canopy lighter in color and cause wilting from the bottom up.

Fusarium infection- early stages
Fusarium infection – late stages

A programmatic approach

By following an agronomic program, you can better position products to control key insects and diseases during mum production. With a built-in resistance management strategy that incorporates different modes of action, agronomic programs provide a framework to help keep your crops healthy.

Mainspring® GNL insecticide is an excellent product to use within a rotation program as it features a unique active ingredient in IRAC Group 28. It provides extended protection from thrips, aphids, worms and other chewing and sucking insects. Mural® fungicide, powered by two active ingredients in FRAC Groups 7 & 11, is an excellent solution for protecting mums against Fusarium, Pythium spp. and Rhizoctonia. The ability to apply both products as a drench offers you the benefit of systemic protection inside the plant and even longer-lasting control.

Be prepared for the season ahead by downloading our program for mums at

All photos are either the property of Syngenta or are used with permission.

©2020 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties and/or may have state-specific use requirements. Please check with your local extension service to ensure registration and proper use. GreenCast®, Mainspring®, Mural® and the Syngenta logo are trademarks of a Syngenta Group Company.

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