Summer Flower Garden Care

Your June and July Flower Garden To-Do List

Summer Flower Garden Chores
Photo: Travel Ink/Getty Images

Spring is a busy time for flower gardeners, and it can be a relief to take a break in the hottest months to enjoy the fruits of your labor. However, industrious gardeners know that a few carefully planned chores may give you more bang for your buck in the flower garden. Continue caring for your annuals and perennials in the summer months to ensure a continuous succession of blooms until first frost.

Deadhead Flowers

Cutting a summer bouquet serves as more than just a way to beautify your living room or kitchen. Most annuals benefit from regular cutting, whether you’re removing spent blooms or whether you’re taking the freshest blossoms for the vase. Cutting annuals produces bushy, vigorous growth, and it spurs the plant to produce more flowers in an attempt to fulfill its mission to produce seeds. Don’t get caught up in trying to save the last two or three spindly blooms on your verbena or sweet alyssum. Shear the entire plant back by a third, and watch for new buds to appear soon.

Concerning perennial flowers, deadheading can control the undesirable spread of plants. Some perennials, such as coneflowers, are notorious for taking over a garden patch with the seeds they drop. Gardeners must weigh their desire for tidiness against the benefits of leaving spent flowers to provide winter interest or food for wildlife.

Stay on Top of Watering

Although established plants don't need the same frequency of watering as your new transplants did at the beginning of spring, don't let drought steal your garden's thunder. An inch of water is necessary for most flowering plants, unless you are tending a xeriscape. Consider using soaker hoses to deliver water right where it's needed to the root system.

 

Keep Weeds in Check

The little dandelion and thistle sprouts that made a tentative appearance six weeks ago have established deep tap roots by now. Get out your two dollar dandelion digger, and plunge it into the soil at the base of the plant to remove as much of the root system as possible. Mature weeds are most likely to relinquish their purchase after a soaking rain. If the weeds are too tough or plentiful to dig out, use a broadleaf herbicide, and protect the neighboring foliage of garden flowers from overspray with a piece of cardboard. 

Control Diseases

By late June, the warm humid nights of summer may have encouraged the growth of foliar diseases like mildew and black spot in susceptible plants. Water your plants in the morning, to give foliage an opportunity to dry quickly when the sun comes out. Avoid wetting leaves unnecessarily by using soaker hoses.

Use sulfur or copper based organic fungicides on plants minimally affected by disease, but destroy any annual plants that show evidence of disease on more than 50% of their leaves. Apply fungicides in the evening to prevent leaf burn. Keep diseased plants out of your compost bin. Discard diseased foliage in your brush pile or bury it so that it can decompose naturally.

Replenish Mulch

The thick layer of mulch that seemed to obscure emerging plants in the spring may be surprisingly thin now. Heat and moisture cause organic mulches to break down rapidly, so add enough mulch to maintain a 3-inch layer around flowering plants, including those growing in containers. The exception is alpine plants like dianthus, which may experience root rot if mulch is applied too close to the plant’s crown. If you’re overwhelmed with green matter in your compost bin, you can use excess grass clippings as mulch in the flower garden.

Apply Flower Fertilizer

In the middle of summer, your annuals and roses may need a fertilizer boost to keep up their performance until the first frost. Your focus should be on adding sources of potassium to boost blossom development rather than nitrogen, which promotes leafy growth.

Liquid seaweed products provide a quick potassium boost, and a top dressing of rock potash provides a long-lasting source of potassium. Put a reminder in your garden journal to reapply liquid fertilizers every two weeks for heavy feeders like dahlias and cannas to keep them productive. 

Start Seeds for Fall Flowers

Save some compost to use as a seed-starting medium for fall flowering plants, like pansies, nasturtiums, and calendula. Start these seeds in an area of the garden sheltered from the direct summer sun. If the entire garden plot is sunny, use shade cloth to protect these cool weather lovers until temperatures become moderate. Start your fall flower garden seeds at least two months before first frost, and you’ll reduce the wait between the last blossom of this season and the first blossom of the next.