After Spring Rains, It's Summer Chores That Keep Your Garden Lush

By Joel M. Lerner
Saturday, June 14, 2008

After plenty of spring rain, gardens are growing lushly again, a contrast with last summer's drought. So it's time to get back to normal garden management activities.

That means you should deadhead flowers, encourage summer blooms, prune shrubs, fertilize, weed, monitor pests, and cut dead and diseased wood from trees and shrubs.

Don't let young plants go dry for longer than a week. Water deeply, and maintain drainage by checking for soil moisture. Use your finger, a dowel or a screwdriver to check wetness. Whatever you use should sink in easily, and soil should not still be muddy within a day or two of watering.

The best treatment for your plants is to lay one to two inches of compost over your beds. The organic material will lighten the soil; make it more fertile; and provide better moisture retention, aeration and drainage. Here's a closer look at some garden chores:

Deadheading

Deadheading flowers can make plants more robust. Pinching or cutting spring flowers as they fade will sometimes encourage plants to re-bloom. This is generally a good practice on all plants where it's practical to reach flowers.

For example, low-growing evergreen dianthus ( D. gratianopolitanus) just flowered. The stalks that held the now-faded flowers should be sheared so the plant will return more densely next spring. And foliage has yellowed on most spring bulbs, so they can be cut to the ground. If you have to dig and save them to replant in the fall, dig now, while you can still find them, and store in a cool dry place.

Flowering stalks on certain bulbous plants should be pruned to the base of stems when flowers fade. This is applicable for day lilies, irises, gladioluses, spider lilies ( Lycoris), leucojums and canna lilies.

Many perennials are blooming now or preparing to make their show. Some of these are Japanese irises, day lilies, salvias, astilbes, nepetas, Shasta daisies and purple coneflowers.

While you carry out your June deadheading chores, clip some fresh flowers that have not faded and bring them indoors to display in a vase. Use room-temperature water, and make a fresh diagonal cut at the base of each stem just before placing it in water.

Pinching salvias and nepetas, as well as removing flowering stems (scapes) of faded flowers on day lilies or repeat-blooming bearded irises, can result in a second flush of flowers. Also, shearing flowers from heirloom bridal-wreath spirea ( Spiraea prunifolia) as they fade will often result in another flush of flowers.

It is also a good practice to deadhead annuals. As soon as one flower is gone, you want the plant to be generating another, especially petunias and geraniums. Pinch or cut flowers from stems.

Annuals

Deadheading, applying fertilizer and growth stimulants, and maintaining moist (not soggy) well-drained soil are the best practices you can use to grow sensational displays of annuals.

Fertilize annuals throughout summer using Jack's Classic, Miracle-Gro or another water-soluble fertilizer that gets fast results. Add liberal amounts of compost, kelp, fish emulsion or other low-nitrogen growth stimulants, such as Bio-Plex, Liquid Bloom from Dyna-Gro, Ocean-Gro Plant Food and Neptune's Harvest Seaweed Fertilizer. These are available at your local garden or home-improvement center.

Slow-release fertilizers that can be used in place of water-soluble varieties are Osmocote Plus Multipurpose Plant Food or any 5-10-5 general-purpose fertilizer. Moisture and good drainage are key to a plant's ability to absorb any of these nutrients. Use only one type of fertilizer, solid or water-soluble. The ocean-based supplements have a different action and thus complement any fertilizer. Use all products according to labeled directions. When using water-soluble material, fertilize every other watering. Fertilizer and growth stimulants will create robust flowering plants that you'll be sorry to lose at first frost.

Pruning

Your hardy chrysanthemums almost certainly returned this spring, considering the mild winter. Pinch the top two to four inches of growth now. Pinch about two inches again two to three more times by the end of July, then stop and let them grow full so they can bud and flower in fall. Fertilize now and again in July with a granular 5-10-5 nutrient sprinkled around each plant. Water it in to make sure plants absorb it. Irrigate during dry spells, and supplement fertilizer with growth stimulants.

Do not cut fading flowers on plants that are expected to produce fruits or berries. For example, the berries of purple beautyberries ( Callicarpa) and hollies ( Ilex) are among their greatest assets. If their flowers are removed, they will not produce berries abundantly. If you did not prune back hard before new growth began, wait until next year to do so. Don't prune forsythia now unless you must because flowers are forming for next year. The same is true for azaleas. Do only selective and light touch-up pruning.

Hybrid tea roses are bred to bloom repeatedly, provided that you clip flowers before petals drop. When pruning fading roses, cut the stem below the fading flower back to a junction of at least five healthy leaflets. This will keep them budding and re-blooming all summer.

Many plants require only light pruning to remain in shape. If they are sited so they can grow to maturity, selective trimming is all that's necessary. Never cut hard at this time of year. Always leave at least two-thirds of a plant's branches.

Long hedges might require shearing. Do this no more than once a year, usually after flowering. If a hedge has no flowering value, such as a yew, arborvitae or juniper, shear after new growth has hardened off a bit, during the summer. Coniferous plants such as pines, spruces, cedars and firs should not be sheared.

Pruning dead wood when seen on trees or shrubs can stave off disease problems before they spread to the rest of a plant. If you are pruning dead or diseased wood, be sure to clean your tool with bleach and then use light oil on blades to protect them from corrosion and before cutting healthy wood.

Prune roots of trees or shrubs that you are planning on moving in the future. Sink a long, square-edged digging spade into the soil in an 18 to 24 inch circle around the trunk, or wider, depending on the size of the plant. Make sure you slice all the way around. Do not move the plant; leave it to grow more roots at the cut. This will ensure greater success when transplanting next year.

Container Plants

You still can create container plantings for your patio, deck or front entry. Follow the nutrient recommendations above for annuals. Plants must have adequate drainage to thrive outside in containers. This is the most important consideration for their health. A hole in the bottom of the planter and a generous layer of stone or foam packing peanuts will ensure that they don't stand in water. Cover with landscape fabric, then use a potting medium over fabric for planting. Some growth mediums that I have used with great success are Gardeners Gold organic potting soil, Baccto potting soil and Miracle-Gro potting soil.

Joel M. Lerner is president of Environmental Design in Capitol View Park, Md. Contact him through his Web site, http://www.gardenlerner.com.