Don’t Ignore Mums in July, It's When Fall Flowers Form – Do These 5 Easy Tasks Now to Ensure Huge Autumn Blooms

Spring purchased garden mums are the best choice for a colorful autumn display and the promise of a return after winter. But don’t neglect mums this summer if you want to ensure lots of blooms in the fall. Even if you dutifully pinch their growth back for a compact shape, there is more to do.

To encourage the most blooms on your chrysanthemums (Chrysanthemum x morifolium), summer care is important. Preventing drought stress, providing ample nutrients, shaping your plant, and eliminating pests, plus a few other easy tasks will ensure your plants are full of flowers in fall.

Mums are offered for sale in late summer and fall, already in bud, but growing mums beginning in spring brings the best return on investment. Often the mums sold in fall are only for seasonal decorative use. So learning to grow your own mums and care for them during every month is the ideal way to get huge autumn blooms.

July Mum Must-Do Tasks

Mums planted in spring should be well established by now and receiving ongoing care for pinching, fertilizing, watering, mulching, and controlling pests. These tips will see your mums through July and beyond.

1. Pinch Plants

Pinching the growing tips on mums starts in spring when the plant is 6 inches (15 cm) tall. Pinch plants again when the newly formed side branches are 6 to 8 inches tall or every four to six weeks. Stop pruning mums by mid-July to allow buds to form. Pinching too late could delay flowering.

To pinch mums, just grasp the tip of each stem above a leaf node and pinch off half an inch to one inch (1.25-2.5 cm) of stems and leaves. Snippers or hand pruners work, too, for trimming. These Felco pruners are a favorite of our gardening experts.

Prune your mum into a rounded shape to keep it tight for fall. Pinching back the stems will force side shoots and keep the plant shorter and well branched for a compact shape with more stems for blooms.

2. Fertilize for Flowers

If you fertilize your mums in spring with a slow-release fertilizer, it should last through July. If the foliage looks lackluster now, you can apply a side-dressing of an organic fertilizer, like this one from Miracle-Gro.

Some prefer a liquid fertilizer, such as 5-10-10 or 10-10-10, which can be applied monthly in July. Follow the label instructions for the correct amount, but you will either need to mix it with water before application or apply it around the root zone then thoroughly water it in.

There are different schools of thought on what fertilizer ratio to use, so establish your own regimen on what works for your plants. If the mums are getting long and lanky, however, they are receiving too much nitrogen fertilizer. Once the buds have formed, you should stop fertilizing.

3. Water Well

Overwatering or underwatering can both sound the death knell for mums. Too much water promotes root rot and too little water results in drought stress. Water mums deeply, but wait till the top of the soil is dry to water again. Avoid wetting the leaves, which can promote fungal issues.

Consistency is key here. Keep the mums well hydrated throughout the summer to avoid drought stress, which can inhibit blooming. A simple drip irrigation system, like this one from Home Depot that Content Editor Laura uses in her garden, ensures plants get water at the base where they need it most.

4. Add Mulch

Mulching is important to moderate the soil temperature during the peak of summer heat, which often occurs in July. Mulch also helps retain an even moisture level and controls weeds. If you neglected adding mulch in spring, do it now so the summer heat does not dry out the soil too quickly.

5. Keep an Eye on Pests

Keep an eye out for pests on your mums as well as your other plants. If you water by hand, that is a good time to scout for intruders. Mums are commonly affected by aphids, which are oval-shaped, sap-feeding insects. Leaf miners are another common problem. They are tiny fly larvae that tunnel through leaves. Spider mites are the other top pest on mums. They are practically invisible, sap-feeding arachnids.

Aphids are large enough to see on the underside of leaves and new shoots, usually in groups, feeding on leaves. Damage includes stunted plants, distorted leaves, and honeydew, which is a sticky substance left on leaves. Control them with blasts of water, insecticidal soap, or neem oil, both of which you can get on Amazon. However, beneficial insects such as ladybugs and their larvae, often control aphids naturally without your intervention.

Leaf miners create noticeable winding tunnels through the leaves. They are difficult to control because they are inside the leaves. Remove the leaves as soon as you see the trails and discard them in the trash. Pick up any dropped leaves and discard in the trash.

Spider mite damage shows up as speckling on leaves from their feeding and fine webbing between stems, on flower buds, or on the undersides of leaves. To control spider mites use forceful sprays of water at regular intervals, insecticidal soap, neem oil, or a miticide. If the infestation is severe, remove the affected leaves and stems.

By following these tips, your mums should be compact, thick with healthy stems, and full of buds by late summer to fall, depending on the variety and your planting zone. Once your mums are in glorious bloom, pinch off the faded flowers and you will be rewarded with successive blooms.