June Garden Almanac
June begins our traditional summer months. The summer solstice, the day with the longest daylight hours of the year, falls on Sunday this year - June 21.
Question: Why is it that we seldom have rain here in Northern California during the summer? Answer: About a thousand miles off the California coast lies the Pacific High, a mass of cool, heavy air that almost always blocks rain storms from reaching us. Because we don't get much rain, the best way to preserve precious soil moisture is to pull weeds and mulch the garden.
Annuals: Cool-season annuals are likely spent and ready to come out of the garden now. Warm-season annuals to plant in June include marigolds, zinnias, phlox, cosmos, calibrachoa, sunflowers, and Paludosum daisies. Feed bedding annuals with liquid organic kelp or fish emulsion once a month to keep them blooming.
Perennials: Water perennials every 10 days if the weather is dry. Remove spent flowers once a week to encourage more blooms. Mulch around plants to conserve soil moisture and keep down weeds. Now is fuchsia season; feed fuchsias with a balanced fertilizer, keep the soil just moist, and remove old blooms and swollen seed pods to keep them blooming.
Container plants: Water container plants whenever the soil dries to 1 inch below the surface. The soil in clay pots and wooden boxes will dry more quickly than the soil in plastic containers.
Roses: Remove spent flowers and hips. Apply a complete, organic granular rose and flower fertilizer in early summer. Deep water roses during dry periods.
Hydrangeas: There's no way around it, hydrangeas need a good amount of water during the heat of summer and early autumn. Group hydrangeas with other water-loving plants to keep the water bill in check. Water deeply and mulch to conserve soil moisture. Hydrangeas bloom on last year's growth - be careful when you prune.
Shrubs: Water shrubs in early morning so that roots can absorb the moisture and move it up into the plants' foliage through the course of the day.
Trees: Fertilize established trees with a complete, organic granular fertilizer. Mulch around trunks and out to the drip-line to conserve soil moisture.
Vegetables and herbs: Replace any cool-weather crops still in the garden with warm-weather crops. There are plenty of warm season months left to plant tomato seedlings in June. Now is the best time to plant peppers and eggplants. Withhold water from garlic, bulb onions, and shallots so that the outer layers can tighten around the bulbs. Lightly cultivate around plants to keep weeds down and keep the soil from crusting.
Fruit trees: “June drop” is the term for fruit falling from fruit trees in early summer. June drop is nature's own way of culling fruit a tree can't support. After fruit drop, you can further pick off fruits that are too close together - pears, plums, and apples; this will allow for large fruit at harvest.
Garden maintenance: Young plants not yet established will need more frequent soaking as the weather warms. Water deeply enough to soak the soil but infrequently enough to allow the soil to dry between waterings. To replace a water-loving lawn you need to kill it first. Do this by covering the lawn with clear plastic for a month. Solarizing will kill the lawn and make it easier to remove. Replace your lawn with water-conserving native perennials and shrubs.
Native plants: Blooming this month is clarkia, columbine, Donner buckwheat, wild mock orange (Philadelphus lewisii), Matilija poppy, blue elderberry, Cleveland sage, Wooly blue curls, and California poppy.
Nature alerts: Western azaleas and wild rhododendrons will be in bloom in shady glens now. Look for these plants along creeks and under young redwoods, firs, and bay trees. Close by you will find the pink and white blooms of Western azaleas on the Azalea Trail along Azalea Creek in Hood Mountain Regional Park.
Kenwood weather averages: Temperature: Average High 80°F, Average Low 52°F, Mean 66°F; Average Precipitation 0.23 inches; Record High 109°F (1960), Record Low 34°F (2011). Sunrise and Sunset: Sunrise on the 1st 5:48 a.m., Sunset on the 1st 8:27 p.m.; Sunrise on the 30th 5:49 a.m., Sunset on the 30th 8:38 p.m. Moon: Full on June 2; Last quarter/waning on June 9; New on June 16; First quarter/waxing on June 24.
- Compiled by Steve Albert
Steve Albert is the author of The Kitchen Garden Grower’s Guide available at Amazon.com. He teaches in the landscape design program at the U.C. Berkeley Extension. He lives in Oakmont.