PLANT VEGETABLES FOR LATE SUMMER, FALL AND WINTER HARVEST

Many vegetables can be planted in July for harvest in late summer, fall and winter. Since we do not usually have frost until mid to late October, even frost sensitive vegetables like corn can still be planted.

Radishes mature in about 3 weeks. By repeat planting every 2 weeks, you have fresh radishes all summer. A planting of carrots in early July will be ready in mid September. Carrots can be wintered over in the ground for harvest all winter long.

Turnips, rutabagas and parsnips are best if they have had some frost before harvest. Planting in July is the best timing for fall harvest. I make repeat sowings of green onions or scallions at about 3 week intervals. They can be harvested until well into November.

Spring planted lettuce and spinach usually bolt and go to seed by mid to late July. Planting now will give you fresh greens for summer and fall harvest. You can begin picking leaf lettuce and spinach in about 30 to 40 days after seeding. Other leaf vegetables which can be harvested in 30 to 40 days include Swiss chard, mustard, collards and kale. All of these leaf vegetables can be cut leaving one inch of stem and will grow new leaves for repeat harvesting.

About 25 vegetables can be planted from mid-summer to fall for winter harvest. Most root and leaf vegetables are frost hardy. Territorial Seed Company (territorialseed.com) has a separate catalog especially for winter gardens. Included in this catalog is a list of planting times. The catalog contains varieties which have been specially selected for winter gardening.

SUMMER IRRIGATION AND MOWING

Rains are no longer keeping up with plant needs so it is time to irrigate. If you plan to irrigate your lawn through the summer, 2 to 3 day intervals between irrigation is better than daily application. Daily irrigation keeps the soil surface moist which encourages weed seed germination. Enough water should be applied with each irrigation to wet the soil to a 6 inch depth. It normally requires about ½ to ¾ inch of water to penetrate 6 inches. You can check your sprinkler system or hose sprinklers by placing shallow cans such as tuna fish on the lawn. Check after a timed interval (such as 30 minutes) to measure the amount of water accumulated. Flowers and vegetables need similar amounts and frequency of irrigation as lawns. Most trees and shrubs will do just fine with weekly irrigation.

Grass develops a stronger and deeper root system if it is not mowed too short. Raising mowing height to 1 ½ to 2 inches will improve its drought resistance.

REMOVE WATER SPROUTS FROM TREES NOW

Water sprouts are fast growing branches which grow straight up. Similar sprouts, called suckers, grow straight up from the base of the trunk or sometimes from large roots close to the trunk. They are most common on fruit trees including ornamental plums. Other deciduous trees will develop them after heavy pruning in the winter or spring. Water sprouts have very weak attachments so they are easily broken in stormy weather. They also clog up the interior portion of trees. The best time to remove both water sprouts and suckers is while they are still soft and flexible. At that time they can be snapped off. They are much less likely to send up another sprout from the same area than if they are cut off. At the base of each sprout are one or more latent (hidden) buds. When the sprout is snapped off (instead of cutting), these buds are removed, resulting in very little re-sprouting. If water sprouts are allowed to grow for a year or more, they can become major branches which need to be sawed off.

LAST MONTH FOR PRUNING SPRING-FLOWERING SHRUBS

If your spring flowering shrubs such as Rhododendrons, Azaleas and Lilacs need pruning, do it (or have it done) by the end of July. Otherwise, some of next spring’s flower buds will be removed in the pruning process. Most spring flowering shrubs set new flower buds during late summer. Some are already developing flower buds. However, you can prune off flower buds and plants will still have time to grow new ones during August and September. If you are only concerned about reducing the size of an overgrown plant, and do not mind sacrificing flowers, spring flowering shrubs can be pruned anytime. Summer flowering shrubs (such as hydrangeas and roses) can be pruned in winter and early spring because they develop flower buds on new growth.

SUMMER WEED CONTROL AND PREVENTION

Summer weeds have a different metabolism system than most ornamental plants. They simply grow much faster during hot weather than most ornamental and food plants. They also mature and set seed more quickly. That is why it is necessary to weed frequently and avoid new weed seed development. Several different materials and herbicides can prevent new weed growth once you have removed weeds from an area.

Most weed seeds require light to germinate. Two inches of compost or bark dust will reduce weed seed germination by 90% by simply reducing the amount of light which reaches the soil surface. Weed barrier fabric mulch will completely block weeds from growing under shrubs and trees. Fabric mulch is porous so it allows water and air to flow through to the roots of plants. Fabric mulch is normally covered with bark or other mulch. After a year or two, weed seeds blow in on top of the fabric. However, they are shallow rooted and easily removed. Black and colored plastic are effective for weed prevention for vegetables (see naturalpruningnw.com/how to guide:vegetables)

My favorite weed preventer around vegetables and flowers is corn gluten. It is a natural organic material safe to use around pets. It is normally only available in full service nurseries and garden stores (not big box stores). Corn gluten is not as effective as treflan or trifluralin: sold as Preen and other brands. Treflan is safe to use around herbaceous plants such as flowers and vegetables. Both of these granular materials are effective for about six weeks. They can be applied before bark mulch application or on top of bark or other mulches.

Casoron is a long lasting granular weed preventer for use around woody plants such as trees, shrubs, vines, blue berries and roses. It will prevent weed growth for up to a year. It will also kill established grass, so be careful not to spill it on the lawn. Weed prevention is best with all of these materials if the soil remains undisturbed by cultivation.

We are available to apply any of these materials for you to make your landscape maintenance easier.

PRUNE FREEZE-DAMAGED SHRUBS

Many broadleaf evergreen shrubs such as Escallonia, Viburnum Spring Bouquet and Choisya (Mexican Orange) were damaged last December and had to be cut way back this spring. Now is the time to pinch with fingers or prune those rapidly growing new shoots to shape the plants and encourage branching near the ground. I typically remove about half the length of shoots when they are about a foot long (or less when they are shorter). This stimulates branching just below where the cut is made.