Monthly Vegetable Gardening Tips
January – Asparagus is a perennial, cool-season vegetable, its long spears coming up year after year. So when you make the bed, do it carefully…your asparagus may be growing in it for 12 to 15 years or longer. Asparagus grows from seed, but it is easier to buy 1 to 2-year-old crowns. The crowns are actually rhizomes (fleshy stems that store food for future plant growth) with roots attached on their under surface and the buds of spears that are just beginning to develop sticking up. UC 157 hybrid is a good variety for this area – it tolerates warmer winters and is resistant to Fusarium. When buying crowns, look for fresh, firm-fleshed roots. If they are shriveled or brittle, they may be old and won’t produce well, if at all. Plant crowns while they are dormant.
Plants need full sun, good drainage, and, most important, well-prepared soil enriched with lots of organic matter (well-rotted manure, compost, bone or blood meal, leaf mold). Asparagus is a good candidate for raised beds. Dig a 6 inch deep trench 12 to 18 inches wide and spread crown roots over slight mounds of soil spaced 12 inches apart; cover with 2 to 3 inches of soil. As plants grow, pull soil over the crowns until the trench is filled.Let spears grow the first year without harvesting any spears (this allows for good root growth); after spears shoot up, let them leaf out so that the foliage can nourish the growing roots and rhizome for future production. Then harvest lightly for 3-4 weeks the next year. The fleshy root system still needs to develop and store food reserves to support perennial growth in future seasons. Plants harvested too soon or heavily may be weak and spindly and the crowns may never recover. Future harvests may be for 6-10 weeks per year. Harvest spears daily during the harvest period when spears are 6-8 inches tall and the tips are still tight. If the asparagus is allowed to get much taller, the bases of the spears will be tough. Snap or cut off each spear just below the soil surface. Cutting too deeply can injure the crown buds that produce the next spears.
When harvest is over, allow spears to grow and leaf out. This helps transfer energy to the roots for good spear development the next season. Asparagus has an attractive, fern-like foliage that makes a nice garden border. The tall growth can shade out other plants, so keep this in mind when deciding where to site your asparagus bed. Some gardeners prefer to support the growing foliage with stakes and strings to keep them tidy. Cut the foliage down to 2 inch stubs after freezing weather or when the foliage turns yellow. A 4- to 6 inch mulch of compost, composted manure, leaves, or other material added at this time will help control weeds and add organic matter and nutrients.
Weed the bed each spring before the first shoots come up to avoid accidentally breaking off spears. During production, it is best to pull rather than hoe weeds, if possible. A light mulch helps keep the soil surface from becoming too hard for the shoots to break through easily. Irrigate the bed during the summer for good spear production.
For additional information, see Growing Asparagus in the Garden from the UC Davis Vegetable Research and Information Center.
Potatoes grow from seed potatoes. Seed potatoes are not seeds, but rather a piece of a potato. Do not be tempted to use grocery store potatoes or potatoes from your own garden. Soil-borne diseases, harmless to humans but potentially devastating for a potato plant, can be carried by potatoes. Instead, buy seed potatoes from a nursery that displays a Certified Seed Potato tag or from a reputable mail-order company that certifies the seed potatoes are disease free. If the seed potatoes are not already cut, cut the tubers into pieces that are about the size of a small chicken egg. You do not need to cut small egg-size seed potatoes. Make sure each piece has at least one eye (small depression where sprouts will form). Store freshly cut pieces at room temperature for 1 to 3 days before planting. This allows the cut surfaces to dry and form a callus, which decreases rotting.Plant when the soil has warmed to about 55°F. In the Sacramento area this is usually late February to early March. A late frost may damage the plants and set them back but is unlikely to kill them. Provide protection for the plants to avoid significant damage. Potatoes need well-drained sandy-to-loam soil; they do not grow well in heavy soils, so they are a good candidate for growing in raised beds. They do best if grown in full sun. Cultivate the soil well, making sure that it is in a loose, friable (crumbly) condition before planting.
To plant, drop the seed pieces into furrows 3 inches deep with the pieces spaced 6 to 12 inches apart. Closer spacing gives more but smaller potatoes at harvest. Fill in the furrow to ground level. When the potato plants are 4 to 6 inches tall, “hill” them up by mounding soil to cover most of the leaves. Three weeks later hill again. This will make furrows between the rows that are at least 6 inches deep. You can also plant the seed pieces in raised beds: dig 3-inch deep holes using the same spacing and “hilling” technique as above. Apply nitrogen fertilizer at planting time.Potatoes can also be grown in half wine barrels. Fill the barrel halfway with potting soil (do not use garden soil). Add three seed potatoes, evenly spaced, and cover with about 3 inches of potting soil. As the foliage emerges, fill the barrel with more soil to cover most of the leaves. Continue adding potting soil as the potatoes grow until the level of the soil is about 2 inches below the rim of the barrel. Mulch the top of the soil with organic mulch (straw, shredded leaves, compost); water and fertilize regularly. Harvest as indicated below by dumping out the barrel, or if it is too heavy, carefully reaching in with your hands to collect the potatoes.
Potatoes are shallow-rooted and need constant soil moisture. If soil dries after tubers have formed, a second growth will start when soil gets moist. This will cause knobby, cracked, or odd-shaped potatoes. Alternate wet and dry conditions can also cause cavities near the center of the potato. Cultivate carefully to remove weeds, taking care not to injure roots and tubers near ground surface.
Blossoming potato plants are sometimes an indication that new potatoes are ready to harvest; however, not all potato plants blossom. About 7 to 8 weeks after the plants emerge from the soil, you can gently use your hands to uncover the sides of the soil mound to harvest small immature tubers (new potatoes, which are extra sweet because their sugar has not yet converted to starch). Take care not to disturb the roots and remaining tubers on the plant. Then carefully pack the soil back around the roots and water the plant well. Be sure that all developing tubers are completely covered by soil. Long exposure to light can cause the skin to turn green. A poisonous alkaloid makes green potatoes taste bitter and should not be consumed. Most of the crop should be harvested when vines die and/or the skin of the tubers is firm, not flaky. Remove vines before digging the tubers. Dig the potatoes when the ground is dry; dig carefully, making sure you do not injure or bruise the potatoes.
For more information on growing potatoes, see Potatoes, white (PDF, 15Kb) from the UC Davis, Vegetable Research and Information Center. Additional information is available in UC ANR Leaflet 2802, Growing Potatoes (PDF, 129Kb).
March – Let your vegetable garden soil dry out a bit (it should be moist but not wet, and dry enough to crumble when pressed in your hand) before you prepare it for planting. Loosen the soil to a depth of 6 to 10 inches with a spading fork and pulverize any clods into pea-sized granules. Spread fertilizer and compost and then lightly work into the soil, rake it in, and lightly water it in. Your beds are now ready to plant warm-season crops.
April – Check your soil temperature with a soil thermometer or compost thermometer before planting warm season vegetables. If the soil temperature has reached 60 to 65°F and the nighttime air temperatures are consistently above 50°F, it is time to plant tomato and pepper transplants. Wait until the soil has warmed to 70°F before planting squash and melons. Be sure to provide protection for the plants if the weather turns cold.
May – Tomato and pepper transplants can be planted this month. Seeds of pumpkins, beans, corn, squash, cucumbers, and melons can be sown in the garden around the middle of this month. For interesting and unusual fall decorations, consider growing pumpkins or winter squash that are unusual and not your ordinary jack-o-lantern. Here are some varieties to consider.
|‘Jarrahdale’ - slate, blue-gray; shape is flat, ribbed, and very decorative||‘Musquee de Provence’ - big, flat pumpkins shaped like a large wheel of cheese; rich brown skin when ripe||‘Marina di Chioggia’ - large turban-shaped fruits with deep blue-green skin|
|‘Rouge Vif d’Etampes’ - beautiful flattened, ribbed large fruits are a deep red-orange||‘Long Island Cheese’ - flat, lightly-ribbed fruits look like wheels of cheese with buff-colored skin|
Handpick the critters and drop them into a bucket of soapy water. If you are not squeamish, you can also step on them or cut them in half with pruners (instant gratification!). For more information about these and other insects, check out UC IPM Online for tips on how to manage pests on vegetables and melons.
August – If there is room in your vegetable garden, think about planting a fall/winter garden. Beets, carrots, and other cool-season vegetables can be planted this month. Check out the Sacramento Vegetable Planting Schedule to see what to plant.
Beet varieties that do well in the Sacramento area are those with a short number of days from seed sowing to maturity (generally those with 60 days or less as listed on the seed packet): ‘Egyptian Turnip Root’ (aka ‘Egyptian Flat’), ‘Ruby Queen’, ‘Golden’ (yellow), ‘Chioggia’ (red and white concentric rings… like a bulls-eye), ‘Albino’ (white), ‘Red Sangria’, and ‘Detroit Dark Red’.
Unusual, colorful carrots that are fun to try include ‘Lunar White’ and ‘White Satin’ (white), ‘Yellowstone’ (yellow), ‘Atomic Red’ and ‘Red Samurai’ (orange-red), and ‘Purple Dragon’ and ‘Purple Haze’ (purple skin with orange flesh).
Sacramento County Master Gardeners have had success growing all of the beet and carrot varieties listed above. See Growing Beets in Sacramento for more information.
With other kinds of melons, a strong, pleasant aroma at the blossom (not stem) end is the best indicator of ripeness. These would include: the green-skinned ‘Persian’, the pink-fleshed ‘Crenshaw’, the yellow-skinned casaba, honeydew, and many European cross types.
A watermelon is a bit more difficult, but good indicators of ripeness include:
·the ground spot (the underside where the watermelon laid on the ground) turning from white to pale yellow
·the tendril opposite the stem of the melon has dried and withered
·the skin of the watermelon has turned from shiny to dull
·there is a dull “thunk” when you rap the melon with your knuckles in the morning.
Then keep your fingers crossed before you cut it from the vine.
November – If cool-season crops are not going to be grown in your garden, and you have harvested all of your summer vegetables, it is time to get your garden ready for winter. Remove all plant material and dispose of it either in your compost bin or in your green recycle container. Do not put diseased, insect-infested plant materials, or weeds that have gone to seed in your compost, as all disease-producing organisms or weed seeds may not be killed during the composting process.Now that the leaves are changing colors and falling to the ground, be sure to rake them up and put them in your compost pile (discard any diseased leaves). If you have more leaves than room in your compost pile, place a layer (shredded if possible – run your lawn mower over them) onto your vegetable beds, planted or not. This is a great organic mulch that will help keep the soil from eroding and crusting, and the leaves will break down over time, release nutrients, and help improve the structure of the soil. And red worms love them! If you still have too many leaves, you can stockpile them in large garbage cans or lawn/leaf bags for use during the next year. Be sure to keep them out of the rain.
This is also a good time to clean and oil your tools so they will be ready for next year. Be sure to store them in a dry location to keep them from rusting.