After a most unusual week of cool weather in early June that kept temperatures around 70 degrees, summer finally arrived in Napa Valley. So now we can expect our cycles of over 100 degrees in the hot spots, including Calistoga, then a little cooling off into the range of 85 degrees to 95 degrees as we enter the hottest months of summer. Mediterranean plants will start to go into a semi-dormant stage with the summer heat. This is a natural cycle for this area, so don't be tempted to over-water; conserving water can be easily achieved by just not over-watering. Master Gardeners continue their Water-Wise Landscaping workshop in July. For more information visit our Web site:

http://groups.ucanr.org/mgnapa/index.cfm.

Planting

* If you are lacking summer color, it's not too late to set out these plants: ageratum, begonias, celosia, chrysanthemums, coreopsis, gazanias, gloriosa daisies, impatiens, marigolds, petunias, portulaca, sea lavender, sweet alyssum, zinnias.

* Start seeds of campanulas, columbine, coreopsis, delphiniums, forget-me-nots, and foxgloves to plant out in September.

* Sow corn and beans seeds directly into the soil by early July.

* Plant potatoes for a late fall crop.

* July is the month to start new plants from herbaceous perennials. Cut five-inch stems and remove flowers of carnations, geraniums, marguerites, Shasta daisies, penstemons and verbenas. Root them in damp perlite.

* Late in the month start seeds of endive, kohlrabi, lettuce and peas. Shade the following seeds for planting out in six to eight weeks: broccoli, Brussels sprouts, cabbage, cauliflower and celery.

* At the end of the month divide overcrowded clumps of iris and spring-flowering bulbs. Replant into beds prepared by deeply digging in organic amendments.

Soil management

* July and August are the best months to solarize your garden soil to get rid of weed seeds, insect pests and diseases. For information on soil solarization, visit the Master Gardener Web site at: http://groups.ucanr.org/mgnapa/index.cfm.

* Deep rooted vegetables such as melons, squash and tomatoes, shrubs and trees need to be watered so that the soil is wet to a depth of 3 feet.

* Renew the mulch around plants to keep them cool and conserve moisture.

* Continue to monitor the soil moisture and check the drip system for clogged sprinklers and emitters.

Maintenance

* Stop pruning these spring-blooming plants now: vines and trees such as azaleas, dogwood, redbud, spirea, forsythia, flowering quince, wisteria and some roses shouldn't be heavily pruned unless they are dormant. Excessive pruning from midsummer into fall will reduce next year's blooms. However, trimming a gangly shoot here and there to maintain the proper shape is fine.

* Encourage more blooms by deadheading (snapping off spent flowers) the annuals and pinching back the tips of chrysanthemums, fuchsias and geraniums.

* Cut back cane berries after harvesting June-bearing blackberries, boysenberries and raspberries. Tie up the flexible new canes.

* Pick up and discard fallen fruit into the trash container as soon as you notice it in order to discourage pests.

Harvest

* Harvest your May and June plantings now: beans, carrots, corn, cucumbers, endive, lima beans, lettuce, peas, radishes, summer squash, Swiss chard and turnips. These may be later in the month: eggplant, peppers, squash and tomatoes.

* Fruit starting to ripen are: figs, nectarines, peaches, plums, early apples and prunes.

Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. Napa County Master Gardeners (www.mastergardeners.org.) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to noon at the UC Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 253-4221, or toll free at 877-279-3065. Or e-mail your garden questions to our Web site. Click on Napa, then on Have Garden Questions?