By Susanne von Rosenberg, UC Master Gardener of Napa County
During this uncertain time, many of us have become more committed to growing our own vegetables. A logical next question is: how can I produce more vegetables in the space I have available? Keep in mind these four principles if you want to increase the yield from your garden: picking the right vegetables, planning carefully, interplanting and extending the season.
Picking the right vegetables simply means picking vegetables that are high producers. One watermelon plant will take up at least as much space as a large tomato plant and you might get only four or five small to medium watermelons. If you plant the right kind of broccoli, you can harvest the main head and then harvest side shoots for many more weeks. If you plant cauliflower, you get exactly one cauliflower.
Also look for varieties that mature relatively quickly. Some broccoli varieties produce a main head in 60 to 90 days from transplant. Some tomatoes can produce ripe tomatoes in as few as 55 days after transplant; big beefsteak tomatoes may take 90 days. Quick-maturing varieties are often referred to as early varieties.
Planning carefully is essential to growing more vegetables in the same space. Know exactly what you're going to plant and where. By having more seedlings ready to plant whenever you finish harvesting a crop, you can substantially increase the volume of vegetables you harvest.
Let's say you planted lettuce, and you plan to replace the lettuce with beans once the weather warms up. With such a plan, at the very least you will have the seeds ready. You can get a little further ahead by starting the beans two to three weeks before you're ready to take out the remaining lettuce, and then planting them as seedlings.
When you know how much food a plant yields and how quickly it will produce, you can figure out how many plants you need and when. You can also plan to save space by “going up.” A trellis on the north side of a garden can allow you to grow pole beans, cucumbers, melons and other vining crops vertically, saving you a lot of space.
I also use flat trellises for my tomatoes rather than space-hogging cages. I tie the vines up with twine made from natural materials. Keeping your trellis on the north side prevents it from shading the rest of your vegetables. If you live in a hotter part of the County, consider using space behind the trellis for plants that prefer some shade during hot weather.
Interplanting, also known as intercropping, is the concept of tucking smaller or faster-growing plants in among larger or slower-growing plants to take advantage of available place. There are many opportunities for interplanting, such as planting basil between tomato plants. Another common grouping is radishes and carrots. Radishes sprout and grow quickly; carrots usually take quite a while to sprout and are still small by the time the radishes are ready to harvest.
Many greens such as arugula, tat soi, mizuna, and Swiss chard grow to harvest size quickly, so you can usually grow them between larger plants, such as cauliflower and broccoli. The greens will be ready to harvest by the time the bigger plants start to fill out. Small plants, such as leeks and garlic, can be tucked in just about anywhere. Cool-season herbs such as dill and cilantro are also good for interplanting because they only last a few months.
If you really want to increase your yield, grow vegetables all year. We are lucky to have a mild Mediterranean climate that allows us to grow cool-season vegetables well into the fall. Planning your garden carefully is even more important for year-round vegetable gardening. As the days gets shorter and cooler, plants take longer grow to maturity.
Your more casual gardening friends will probably be surprised when you tell them in mid-July that you just seeded broccoli and cauliflower for your fall garden. But when you plant out seedlings in mid-August, you will have mature broccoli by mid to late October. Because there is less sunlight and the days are getting cooler, broccoli seedlings you set out at the end of August may not mature until mid to late November. Planting just two weeks later in the fall means that you harvest about a month later.
One final thought: As you increase the productivity of your garden, it's even more important to amend your soil and provide adequate fertilizer for your plants.
What are you going to do this year to get more food from your garden?
The UC Master Gardeners of Napa County are volunteers who provide University of California research-based information on home gardening. To find out more about home gardening or upcoming programs, visit the Master Gardener website (napamg.ucanr.edu). Our office is temporarily closed but we are answering questions remotely and by email. Send your gardening questions to email@example.com or leave a phone message at 707-253-4143 and a Master Gardener will respond shortly.
- Author: Monica Finigan, UC Master Gardener Napa County
Tomatoes are a mainstay in most summer gardens. Delicious in warm-weather salads, they are also essential to many cooked dishes. And the plants require far less water to grow than many other vegetables. Here are some tips to help ensure a successful harvest.
Wait to plant until all danger of frost is past and the soil is sufficiently warm. Cool weather makes tomato plants more susceptible to diseases and pests and slows plant growth.
Prior to planting, “harden off” tomato seedlings by placing them outside for about a week. Put them in a sheltered location, and then gradually expose them to garden conditions. If frost threatens, bring the plants indoors or cover them.
Choose stocky transplants six to eight inches tall with healthy green leaves. Check the bottom of the container. If roots are growing out the bottom, the seedlings may have been in the pot too long and may be root bound.
Water seedlings a few hours before planting and make sure the soil in the planting area is moist. Pinch off all but the top two sets of leaves. Carefully remove each seedling from its plastic pot without handling the fragile stem. Loosen the roots. Set the seedling in a planting hole deep enough to cover the exposed stem when the hole is backfilled. Those little hairs on the stem will form roots if buried and will help give your plant a good foundation.
If the seedlings are in biodegradable pots, you can plant them in the pot, but break up the pots slightly so the roots can easily grow into the soil.
Fill the planting hole with soil, press the soil firmly around the plant, and then water the area thoroughly.
Tomatoes need full sun and plenty of room to grow. If planting in a pot, choose a large one. If planting in the ground or in raised beds, space seedlings 24 to 30 inches apart. If you don't intend to stake or cage them, they will need even more room.
Most tomato plants benefit from some type of support. Cages or stakes keep them off the ground, maximize space and make harvesting easier. I like the rectangular wire cages that collapse for winter storage.
Place cages around seedlings soon after planting to avoid damaging the plants. Insert two strong stakes on both sides of the cage to provide support when the plant becomes heavy with fruit. Check the ultimate height of the variety you are planting to determine the height of the cage you need. The openings in the cage should be large enough to accommodate your hand at harvest time.
If you prefer to stake your plants, select stakes six feet long and one and one half to two inches wide. Drive them one foot into the soil four to six inches from the plant. As the plants grow, pull the stems toward the stakes and loosely tie them at intervals of ten to twelve inches. Use strips of cloth or other flexible material. Prune the plants to a few main stems to keep them from becoming too heavy.
Tomatoes need regular watering. Fluctuations in soil moisture can promote fruit cracking and blossom-end rot. Keep the area weeded. Weeds compete with your tomatoes for nutrients and water and can harbor pests. A three- to four-inch layer of mulch will minimize weeds and help retain soil moisture.
Don't fertilize until the plants are flowering and fruits are forming. Too much nitrogen fertilizer in the beginning will encourage green growth but will delay fruit formation. Once the plants start fruiting, give them a nitrogen fertilizer every four to six weeks. Follow the instructions on the label. Place the fertilizer alongside the growing plants in shallow grooves or on the soil surface. Water it in thoroughly.
Harvest tomatoes when they reach full color. Store at room temperature—not in the refrigerator—to enjoy their flavor at its best.
Tomato Plant Sale: U. C. Master Gardeners of Napa County will hold their fourth annual Tomato Sale and Education Day on Saturday, April 23, from 9 a.m. until sold out, in a new location at 1710 Soscol Avenue, Napa. Choose from 28 varieties, including heirlooms and new varieties in a range of colors. These healthy, Master Gardener-grown seedlings include types for fresh eating and for sauce.
Master Gardeners are volunteers who help the University of California reach the gardening public with home gardening information. U. C. Master Gardeners of Napa County ( http://ucanr.edu/ucmgnapa/) are available to answer gardening questions in person or by phone, Monday, Wednesday and Friday, 9 a.m. to Noon, at the U. C. Cooperative Extension office, 1710 Soscol Avenue, Suite 4, Napa, 707-253-4143, or from outside City of Napa toll-free at 877-279-3065. Or e-mail your garden questions by following the guidelines on our web site. Click on Napa, then on Have Garden Questions? Find us on Facebook under UC Master Gardeners of Napa County.