Archived - Home Vegetable Gardening in Washington (Home Garden Series)

Site-Specific Growing Conditions

Convenience is important as you select a vegetable garden site, but full sun exposure and suitable soil are more important. Most vegetable crops require at least six hours of direct sunlight each day, so locate your garden for maximum exposure to available sunlight. Also take into account that vegetables require fertile, well-drained soil. If you live in an area that receives heavy rainfall, soil drainage is especially important.

Soil drainage is determined mostly by the site but can be improved by using raised beds. Select a location with enough slope for surface drain-age and sufficient subsoil permeability to allow water to drain through. You can add fertilizers to improve soil fertility and use organic matter to improve soil structure. If you are in an area where soils may be contami-nated with heavy metals from heavy industry or old orchard practices, consult with your local Extension office or health department about how to conduct a soil test.

One of the most important factors to consider when selecting vegetable crops to grow in your garden is climate. Climate includes length of growing season (Figure 1A), first and last frost dates (Figures 1B and 1C), as well as temperatures during the season. The USDA plant hardiness zone map (Figure 2) provides information regarding extreme minimum temperatures for Washington.

Vegetables are generally divided into warm-season (summer) crops and cool-season (fall/winter/spring) crops (Table 1). Many warm-season vegetable crops require a longer growing season or warmer temperatures than are available west of the Cascade Mountains. In areas where temperature is limiting, row covers and plastic tunnels may be used to successfully grow these crops. Many cool-season crops can be grown throughout the winter in areas west of the Cascades, depending on the microclimate.

The wide assortment of vegetable plants that are commercially available have been selected for their performance under “normal” garden conditions, but in order to get the best results for your garden, you should also consider your specific microclimate and growing conditions. For example, the cool springs in western Washington can make it difficult to get good germination of crops that prefer warm soils. Refer to Gardening in the Inland Northwest (Fitzgerald 2001, MISC0304) for detailed growing guidelines suited to that area.

Crop Selection

What you decide to grow in your vegetable garden depends on what you want from it. For example, you can trim your food budget by growing the more expensive vegetables that your family normally eats. Tomatoes, summer squash, and peppers usually cost more per pound in the store than other vegetables. Yet these crops can be productive in home gardens and require less space to grow than potatoes, cabbage, and winter squash which cost much less per pound.

Some vegetables such as tomatoes, sweet corn, and peas have better flavor and quality when they are picked at their prime maturity and prepared immediately after harvest. Other vegetables such as cabbage, potatoes, and onions can be left in the garden for several weeks after they reach harvestable size with little loss in flavor or texture. If your purpose is to grow vegetables that taste better than what you can buy at the grocery store, concentrate on those that benefit most from immediate use after harvest. Table 2 compares the relative quality, productivity, and monetary values of commonly-grown vegetables.

To obtain fresh food from your vegetable garden throughout the season, make small plantings of each crop two to four times during the season so they mature in manageable quantities over time. If your intent is to can, dry, or freeze vegetables to eat later in the year, plant in large blocks so each crop is ready for processing at one time. Some vegetables such as winter squash, potatoes, and onions can be kept for several weeks or even months in a cool, dry storage room, such as a garage. Table 3 provides a guide for how many pounds of vegetables the average adult consumes in one year, both fresh and processed. Use this information to help you decide how much to plant of each crop for your household.

Tools and Equipment

Only a few basic tools are needed for gardening. Many experienced gardeners use only a spade, rake, hoe, and trowel (Figure 3). Power tools can save labor and time in large gardens but have questionable value in smaller garden plots. Gardens of 1,000 square feet or less can be pre-pared and cared for with only a spade for turning the soil, a garden rake for smoothing the surface and pulverizing clods, a hoe for cultivating weeds, and a trowel for transplanting. Choose good quality tools that are comfortable for you to use.

for smoothing the surface and pulverizing clods, a hoe for cultivating weeds, and a trowel for transplanting. Choose good quality tools that are comfortable for you to use.

Keep digging tools such as garden spades and round-point shovels sharp so that you can cut easily through the soil profile with a minimum of effort. When digging, cut widths of only 2–3 inches and turn the soil over, lifting the shovel only slightly. Overloading the shovel strains both the shovel handle and the gardener’s back, and does little to speed the tilling task.

Garden hoes are slicing tools designed to cut off plants at or slightly be-low the soil surface; never chop with a garden hoe. Round-top hoes and narrow-bladed onion hoes are designed to cut on the pull stroke. Flat-bladed scuffle hoes are designed to cut on the push stroke. Either type is designed to slice along the surface or in the upper one-half inch of soil. For deeper cultivation, use a triangular-shaped Warren hoe or three-tined cultivator. Combination tools that have slicing and cultivating edges are popular with some gardeners.

Vegetable Planting

Seeds

Use care and precision in planting vegetable seeds. Consult Table 4 for specifications regarding planting depth and spacing, germination, temperature, and days to maturity for most vegetable crops. Most seed packets provide directions for specific varieties. If planting depth is not specified, a general rule is to plant two times as deep as the diameter of the seed. Plant seeds slightly shallower in clay soils and slightly deeper in sandy soils.

Most vegetable seeds require moist and fine soil in a firm seedbed for successful germination and establishment. The top 2–6 inches of soil should be light and well-aerated. Rake the top of the bed to create a flat surface and crumble clods so that soil is smooth and fine. Seeds planted in cloddy soil will germinate poorly and often die, as the soil dries out quickly.

Form the seeding row with a hoe or a narrow stick. After sowing the seed, cover to the recommended depth and firm the soil over the seed. This can be done by gently tapping the row with the flat side of a hoe or rake for small seeded crops or walking one time over the seed row for large-seeded crops. In dry areas, form the seeding row at the bottom of a slight trench which will trap precipitation and irrigation water, keep-ing it around the plant where it is needed. In areas with heavy rainfall, plant in raised beds (see below) to allow for water drainage.

Sow seeds thinly but evenly. Spread small seeds evenly by gently tap-ping the edge of the seed packet to move the seeds over the edge a few at a time. Alternately, place a small amount of seed in the palm of one hand, take a small pinch of seed between the fingers of your other hand, and slowly move your fingers back and forth to drop seeds one at a time. It is difficult to sow small seeds thinly enough, so the stand will usually have to be thinned to the recommended row spacing after the seeds have germinated. Plant large seeds such as beans, corn, and squash at the recommended row spacing to avoid having to thin the stand later.

While it is not necessary that each plant have the exact recommended spacing (Table 4), the average density should not exceed those recommendations. If planted too far apart, vegetable plants will not reach their op-timum yield. Additionally, weeds will be more likely to grow in the open area. If planted too close, plants will compete with their neighbors for light, water, and fertilizer. An overly dense planting is also more likely to have disease. These issues will decrease vegetable yield and quality.

Fall crops such as cabbage, kale, broccoli, and lettuce can be direct-seeded in the garden in short dense rows or patches and transplanted as needed (Figure 4). Transplant fall crops into areas where spring or sum-mer crops have been completely harvested and the plants have been removed by cutting them off at the soil surface. This leaves roots in place and causes the least disturbance to the soil. By leaving the roots in place, they will decompose deep in the soil, leaving channels that allow water to drain and worms to move more freely.

Suggested seeding, transplanting, and harvesting dates for most vegetable crops are listed in Table 5. Experiment with these dates in your area and adjust as needed to create a year-round vegetable production calendar that is tailored to your growing conditions.

Transplants

One way to achieve an earlier harvest date for vegetables is to trans-plant them into your garden. Most vegetables can be readily transplant-ed with the exception of root crops such as carrots, beets, and radishes. An advantage of growing your own transplants is that you get to choose the specific varieties for each crop. Oftentimes stores only sell nation-ally-recognized varieties and these may not be best-suited for your area or taste preference. A sunny, warm area is the main requirement for growing transplants. All vegetable plants need high light intensity to develop normal growth. Less than full daylight exposure causes spindly, weak growth which will not produce satisfactory transplants. Warm-season vegetables such as tomato, pepper, and eggplant prefer 70–75°F day temperatures and 55–60°F night temperatures for best development.