In the Garden
Spring Into Food Gardening!
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Food Garden Tips
April Food Garden Tasks and Tips
For what to plant this month, click here.
- COMPOST! MULCH! WEED! These actions will help you keep moisture in the soil during our hot dry season. Lightly incorporate 2-4 inches of compost in your soil to retain moisture, improve soil health and to see higher yields with the same amount of water. Or, you can simply add a 2” layer of compost on top of the soil. Let irrigation and the macroorganisms move the nutrients into the soil. Add 3-4” of mulch (straw, decaying leaves, grass clippings, etc.) to retain water, cool soil and suppress weeds that compete with desirable plants for water. Or, simply add more compost. Leave a gap around the collar/stem of plants to avoid rot. Strawberries and blueberries prefer acidic mulch such as pine needles; straw is also good. Coffee grounds also work well on blueberry beds. If you want to add 2 inches of compost in an 8 x 4-foot raised bed, you will need 0.20 cu yd of compost. If you want to add 4 inches of mulch to the top of this bed, order 0.40 cu yd of mulch.
- Rely on compost as your slow-release fertilizer. Caution: If you add too much compost or additional high nitrogen fertilizer, you may see a green flush of growth that will require extra water and will attract more sucking insects.
- Start irrigation when there is insufficient moisture in the soil. However wet the winter, Sonoma County has water availability issues, so always plan to conserve water. Check the soil daily. Dig to the active root zone level or use a probe to check soil moisture. Watch plants for signs of stress (wilt; dull leaf color). When the weather is hot, a good strategy is to divide the plants’ weekly water needs into single daily applications so that there is even soil moisture. If you can only water very other day, then double the daily amount.
- Currently, April 15 is the average last frost date in the county. This is just an average in a county with many microclimates. Low spots in Sonoma County can have a frost risk into May, but for many of us April is when we start planting our summer veggies. Watch weather predictions and protect any warm weather crops set out before the end of the month. See the list of plants that can be planted safely in April.
- When buying transplants, look for uncrowded sturdy seedlings. Stay away from thick peat pots that don’t decompose well in Sonoma County’s hot, dry summer. Also, look for crops and varieties that are “drought-tolerant” or “drought-resistant.” Don’t be tempted by large flowering plants in small pots—they will be root bound and will have depleted the soil nutrients. Check out our “Drought Resistant Crops and Varieties” guide.
- Build or purchase trellises for spring/summer crops that may require support or that you wish to grow vertically. Peas, beans, cucumbers and tomatoes are easy to grow on a trellis or in an upright cage. Install the trellis before planting. Potato towers also save space and provide a long harvest if you layer late-, mid- and early-season varieties in the tower.
- Continue to thin/harvest any root and salad crops for proper spacing.
- During the spring bloom period, fertilize citrus. For mature trees use 3 lbs of urea or 20-30 lbs of animal manure (reduce for smaller trees), splitting the application into three: April, June and August. Citrus is a heavy water user. Consider waiting until fall before buying and planting new trees.
- If you haven’t already done so paint, or re-paint, the trunks of your deciduous fruit trees to protect from sunburn. Note that the half-and-half mixture of white latex paint and water we usually recommend is not organic—there are organic tree-trunk protection products available online but they do cost more.
- Codling moth can be a significant problem for apple and pear trees. If you had “wormy” fruit last year, spray summer oil weekly during the egg-laying period, which is anytime moths are flying. An option for backyard orchards is hand thinning to remove all infested fruit during each generation (before “worms” leave fruit) and removal of dropped fruit.
- Most grape varieties are susceptible to powdery mildew. Once it appears, it is too late to treat. Powdery mildew is controlled during the growing season by spraying with water-soluble sulfur. Begin applying treatments when all buds have pushed. Thereafter, repeat at ten-day intervals in the spring if disease pressure is high.
- As spring planting begins in earnest, select disease-resistant crop varieties (especially important in a small garden where crop rotation is difficult). The abbreviations on the tag are important (e.g., “VFN” means that a plant is resistant to Verticillium wilt, Fusarium wilt and Nematodes).
- If earwigs are gnawing on your plants, trap them with rolled newspaper, bamboo tubes or short pieces of hose. Place these traps on the soil near plants just before dark, and shake accumulated earwigs out into a pail of soapy water in the morning.
- Click here for ongoing monthly tasks.