«Susan M. Bell • W. Michael Colt • Hugh W. Homan • Dale O. Wilson Planning an Idaho Vegetable Garden Susan M. Bell • W. Michael Colt • Hugh ...»
Susan M. Bell • W. Michael Colt • Hugh W. Homan • Dale O. Wilson
Planning an Idaho
Susan M. Bell • W. Michael Colt • Hugh W. Homan • Dale O. Wilson
©1996 University of Idaho College of Agricultural and Life Sciences
1st printing 1996; 2nd printing 2008; 3rd printing 2010; 4th printing 2012;
5th printing 2014
Issued in furtherance of cooperative extension work in
agriculture and home economics, Acts of May 8 and June 30,
1914, in cooperation with the U.S. Department of Agriculture, Charlotte V. Eberlein, Director of University of Idaho Extension, University of Idaho, Moscow, Idaho 83844. The University of Idaho provides equal opportunity in education and employment on the basis of race, color, national origin, religion, sex, sexual orientation, age, disability, or status as a disabled veteran or Vietnam-era veteran, as required by state and federal laws.
Table of Contents Taste the difference 5 Site selection 6 Soil preparation and fertilization 6 Garden layout 11 Intercropping 12 Companion crops 12 Double cropping 14 Seed sowing 14 Setting out plants 18 Weed control 19 Insect control 21 Perennial vegetables 22 Annual vegetables—greens 24 Annual salad vegetables 25 Annual root vegetables 26 Vine vegetables 29 Legumes 32 Cabbage or cole group 33 Onion family 35 Fleshy-fruited vegetables 37 Resources 39
List of tables:
Table 1. Organic fertilizers 8 Table 2.
Inorganic fertilizers 10 Table 3. Sample garden plot 13 Table 4. Vegetable planting chart 15 About the authors Susan M. Bell is extension educator-horticulture at the Ada County Extension Office. W. Michael Colt is a retired extension horticulturist at the Parma R&E Center. Dale O.
Wilson, Jr., was a seed physiologist at the Parma R&E Center. Hugh Homan is extension entomologist emeritus. All are with the University of Idaho College of Agricultural and Life Sciences.
Taste the difference Home vegetable gardening is a popular pastime for many reasons. Some of us garden for mental relaxation and exercise. Many want to save money or prefer the improved flavor of home grown produce, and some want to simply grow unusual cultivars, which are unavailable at grocery stores.
Whatever your reason is for gardening, this publication will help get your vegetable garden underway.
An early start is one key to a successful garden. Crops such as beets, onions, chard, carrots, lettuce, spinach, the cabbage family, radishes, peas, and turnips grow well in an early garden. Warm weather crops, such as corn, tomatoes, peppers, eggplant, beans, melons, and squash require all danger of frost to have passed before seedling emergence or transplanting.
Fall soil preparation of the garden will help you get a quicker spring start. A small, carefully-tended garden produces as much or more than a large neglected garden. Beginning vegetable gardeners are advised to start with a small garden spot, maybe 10 x 10 feet, using just a few different vegetables.
A garden 30 x 30 feet is large enough for a family of four.
If you plan to can, freeze, or dehydrate your produce, then plant a larger garden.
Site selection The size and location of your garden will often be determined by the area available to you. A small garden can be grown in containers on a patio if land is not available. To avoid soil diseases from building up, use new soil in pots and rotate vegetable families to other areas of the garden each year.
If you have the opportunity to choose, select an area that will have as much sunlight as possible because most vegetables need 6 to 12 hours of full sunlight for bountiful production.
Avoid low, wet areas that are slow to dry out and slow to warm up in the spring. Select a site not infested with tree roots or perennial weeds. If perennial weeds are present, eradicate them one year prior to beginning the garden.
Soil preparation and fertilization To prevent damaging soil structure, prepare your garden spot when the soil is not overly wet. To determine if the soil is dry enough to work, squeeze a handful of the soil into a tight ball and break it apart with your fingers. If the ball crumbles easily, it is safe to spade or rototill, but if the soil clings together like modeling clay and is sticky, it is too wet to work.
The best garden soil is a sandy loam, but rarely will you have a choice of soils. You’ll just have to use what’s available. Physical soil conditions and soil fertility improve with annual applications of organic matter such as shredded leaves, compost, or livestock manure. The main benefit of adding organic matter is to improve the soil’s drainage and workability and its nutrient and water holding capacity. Some types of organic matter are better than others. For example, uncomposted manure, straw, or hay may introduce new weeds to the garden.
Organic matter, incorporated in the fall, will have ample time to decay prior to spring planting. Apply manure at a rate of 30 to 40 pounds for each 100 square feet of garden. Work it into the top 8 to 12 inches of soil. If the garden is small, figure a cubic foot of manure to 100 square feet of garden.
(Table 1 lists some figures to use for manure application.) Poultry manure is high in nitrogen. For this reason, reduce the amount used by half to prevent plant burns due to excess salts. If a tough, woody material like rotted sawdust or straw is incorporated, add a high nitrogen fertilizer such as ammonium sulfate (21-0-0) at the rate of 1 cup fertilizer for each bushel of sawdust added. No more than 2 to 4 inches of uncomposted organic matter should be added at any one time because nitrogen deficiency can result.
Gardens will grow without the use of commercial fertilizers if organic or green manures are added annually. (A green manure is a crop specifically grown to be rototilled into the soil while it is green and immature to help improve soil nutrients and structure.) Whether plant nutrients are added in the form of organic materials or as inorganic salts like those found in commercial fertilizer, plants can only absorb nutrient elements in an inorganic form. Consequently, organic materials must be broken down into inorganic elements by soil microbes before absorption by a plant can occur. (Microbes are beneficial soil fungi and bacteria.) Organic fertilizers are usually slow release materials with low analyses, and often it will take a larger amount of such materials to obtain the desired rate than when a high analysis commercial fertilizer is used. However, organic fertilizers help improve soil structure by adding beneficial organic material to the soil while commercial fertilizers do not. Table 1 lists some organic fertilizers with different analyses and the rates at which they should be used.
1) Acid forming; needs limestone supplement if used in large amounts.
2) Should be composted or applied in the fall. Composts and livestock manures vary widely in nutrient content. Consequently, analyses and amounts to apply are only estimates.
3) Be sure sawdust is well rotted. Additional nitrogen will be needed.
4) Alkaline: do not use if pH is above 7.
A fertilizer analysis (the three hyphenated numbers in Table
2) is shown on all fertilizer containers. The first number gives the percentage of nitrogen (N) in the package, the second, the percentage of available phosphorus (P) and the third, the percentage of water soluble potassium (K). A fertilizer analysis of 10-10-5 contains 10 pounds N, 10 pounds P and 5 pounds K per 100 pounds of fertilizer. A fertilizer analysis of 16-20-0 contains 16 pounds N, 20 pounds P, and no K per 100 pounds of fertilizer. Table 2 lists some inorganic fertilizers.
2-3-2 10.0 20 4-10-10 5.0 10 6-10-4 3.4 6.6 8-10-8 2.4 5 10-10-5 2.0 4 11-55-0 2.0 4 12-12-5 1.6 3.3 13-13-13 1.5 3.3 15-10-0 1.2 2.6 16-20-0 1.2 2.6
If you have a fertilizer showing an analysis not listed in the tables, follow the package directions or select the closest analysis with a similar nitrogen rate from the table and apply that recommended rate. For example, a 10-10-5 analysis recommends applying 4 cups per 100 square feet. A 10-10-10 fertilizer would use that same recommended rate. Check with your local University of Idaho Cooperative Extension Educator to determine requirements for phosphorus, potassium, and micronutrients in your particular area. Have your soil tested to determine your soil’s fertility and fertility potential. For a more complete review of soil fertility in Idaho gardens, refer to University of Idaho CIS 922, “Fertilizing Gardens.” Fertilizer may be broadcast before seeding and tilled into the soil or it can be side-dressed (laid in a narrow band near the row). When side dressing, put the fertilizer 2 to 3 inches below the soil surface and 4 to 6 inches to one side of the seed row. Do not put fertilizer in direct contact with the seed, as it may kill the germinating plant.
Garden layout How you decide to design your garden is a matter of personal choice and convenience. Planting perennial vegetables such as asparagus, rhubarb, and horseradish to one side of the garden will keep them out of the way when rototilling. Put tall growing vegetables such as sweet corn, staked tomatoes, and pole beans on the north side of the garden to avoid shading low growing crops, unless shade is desired. Some gardeners like to plant early seeded, fast growing, quick maturing crops such as lettuce, radishes, spinach, and green onions in one area for easy harvest, while grouping long season crops such as sweet corn, tomatoes, squash, and cucumbers elsewhere.
Consider wide rows and raised beds as two methods of garden layout. Compared to single rows, wide rows are a more efficient use of space that leaves less area open to weeds.
Wide rows may be 2 to 4 feet wide, whichever width works best with your arm length and irrigation method.
Raised beds are an excellent way to warm up clay soils more quickly in early spring and allow for better drainage.
Raised beds may range from 6 inches in height to 2 feet or more. The higher the bed, the less bending is required during garden maintenance. There are many ways to design your garden for fun and productivity.
Intercropping (interplanting) For more efficient use of space, try intercropping. Intercropping is the use of two or three crops in the same area, often combining fast growing crops with slow maturing crops for maximum use of space. The fast maturing crop is harvested before the slow maturing crop shades the area or requires the space.
Examples of intercropping are growing green onions or leaf lettuce between tomatoes, growing spinach or radishes between corn or growing radishes between cabbages. Intercropping is one of the most important techniques that you can use to increase the productivity of your garden. It ensures that no space is left idle and makes the most efficient use of light, soil nutrients, and moisture. Also, by keeping a canopy over the soil at all times, weeds are reduced.
Table 3. Sample garden plot (50' x 100') Double cropping (succession cropping) Many vegetable crops occupy garden space for only a couple of months.
In warmer areas of Idaho, the garden season can last up to seven months. Double cropping—like intercropping—is another valuable method of increasing garden productivity. It can double total potential yields from a given space and help keep weeds down. Double cropping is accomplished by planting an early frost-hardy vegetable that matures quickly. Following the harvest of that crop, the same space is planted with a frost-tender vegetable. For example, after harvesting lettuce, radishes, spinach, green onions, or similar vegetables, the same area may be used for growing warm season, frost tender vegetables such as tomatoes, cucumbers, peppers, eggplant, bush beans, and sweet corn. In a similar manner, cold-tolerant vegetables such as peas and spinach can be grown in the fall after warm season crops are harvested. This allows for a third crop using the same patch of ground.
planted deeper and may not need additional water until after emergence. Planting in rows helps you find the seedlings when they are small, but planting in beds maximizes space.
Most people plant more seed than needed, and thin later to obtain the desired spacing after the seedlings emerge. This practice eliminates some of the risk associated with poor seed quality and unfavorable environmental conditions. (Thinning distances are also indicated in Table 4.) To tell if your soil is ready for planting, squeeze a handful of soil into a ball. The soil ball should not be sticky or wet, and it should break apart when dropped onto a hard surface from a height of 4 inches. If the soil is too wet, wait a week and try again.
Setting out plants You can grow your own transplants indoors to save money or purchase them from a garden center or greenhouse to save time. Transplants must be set out at the proper time of year to avoid frost injury. Otherwise invest in some form of frost protection such as plastic or gauze-like row covers, or wax paper hotcaps. Before transplanting, saturate the soil in the pots to prevent root injury and lessen transplant shock.
Set transplants in the garden slightly deeper (about an inch) than they were growing in the flat or pot. Tomatoes can be set several inches deeper because roots will form along their stems. When transplanting tiny seedlings, hold the plant by the root ball or leaves to avoid pinching or damaging the stem. Containers should always be removed before planting to prevent root constriction. An exception might be when roots have grown into and out the sides of a thin peat container. If this happens, tear the top of the container off to prevent wicking from the root ball. To avoid permanent stunting due to girdling roots, slice the root ball on 2 to 4 sides 1/4 to 1/2 inch into the ball. (Girdling roots take the shape of the pot.) The best time to transplant is on a cloudy day or in late afternoon. In hot weather, shade the plants for a few days to prevent wilting. Try using cardboard or wide boards placed on the south and west sides of the plant. In windy weather you may want to cover the plants with hot caps to prevent damage.