Step 6 - Plant Your Vegetables Right - Illinois Vegetable Garden Guide - University of Illinois Extension

Step 6 - Plant Your Vegetables Right

Much of the success of your garden depends on when and how your vegetables are planted.

When to plant. How early you can plant depends on the hardiness of the vegetables and the climate in your area. Certain vegetables can withstand frost while others cannot. In Table 3 vegetables are classified as hardy, half-hardy, tender, or very tender. This information along with the date of the average last 32 freeze in your area will help you to determine safe planting dates.

Planting by the moon is a favorite topic for discussion among many gardeners. There is no scientific evidence to support planting by the moon; planting studies have shown no relation between the different phases of the moon and good production of crops.

How to plant. There are no magic tricks or difficult techniques in starting seeds or in setting plants. But there are some simple steps you should follow to insure success.
seed planting

Seeds. In starting seeds in the garden, follow these directions:

  1. Use disease-free seed.
  2. Mark out straight rows to make your garden attractive and to make cultivation, insect control, and harvesting easier. To mark a row, drive two stakes into the ground at either edge of the garden and draw a string taut between them. Shallow furrows, suitable for small seed, can be made by drawing a hoe handle along the line indicated by the string. For deeper furrows, use a wheel hoe or the corner of the hoe blade. Use correct spacing between rows.
  3. Hill or drill the seed. "Hilling" is placing several seeds in one spot at definite intervals in the row. Sweet corn, squash, melons, and cucumbers are often planted this way. Hilling allows easier control of weeds between the hills of plants. "Drilling," which is the way most seeds are sown, is spacing the seeds by hand or with a drill more or less evenly down the row.
  4. Space seeds properly in the row. The number of seeds to sow per foot or hill is suggested in Table 2. Space the seeds uniformly. Small seeds sometimes can be handled better if they are mixed with dry, pulverized soil and then spread.
  5. Plant at proper depth. A general rule to follow is to place the seed at a depth about four times the diameter of the seed. Cover small seeds such as carrots and lettuce with about to inch of soil. Place large seeds such as corn, beans, and peas 1 to 2 inches deep. In sandy soils or in dry weather, plant the seeds somewhat deeper.
  6. Cover seeds and firm soil. Pack soil around the seeds by gently tamping the soil with your hands or an upright hoe. This prevents rainwater from washing away the seeds.
  7. Thin to a desirable number of plants (see Table 2) when they are young. Remove the weakest plants. Do not wait too long before thinning or injury will result from crowding.

Table 3 : Planting Chart - Timing

Vegetable Hardiness Recommended planting period for central Illinois (b) Time to grow from seed to field (c)
For overall
Asparagus Hardy Mar.15-Apr. 15 .
Bean, bush, lima Very Tender May 10-June 15 .
Bean, bush, snap Tender Apr. 25-July 15 .
Beet Half-hardy Apr. 10-July 15 July 10
Broccoli Half-hardy Apr. 10-May 1
July 1-15
. 4-6
Cabbage Half-hardy Apr. 10-July 15 June 10 4-6
Carrot Half-hardy Apr. 10-July 15 May 15
Cauliflower Half-hardy July 10-20 . 4-6
Chard Half-hardy Apr.10-June 1 .
Corn, sweet Tender May 1-July 9 .
Cucumber Very Tender May 10-June 15 . 4
Eggplant Very Tender May 10-June 15 . 8-10
Endive Half-hardy Apr. 1- May 1
July 1-Aug. 15
July 10
Garlic (spring planted) Hardy Mar. 25-Apr. 15 Apr. 1-10
Garlic (fall planted) Hardy Sept-Oct (see note e)
Kale Hardy Apr. 1-30
July 1-Aug.1
July 10
Kohlrabi Hardy Mar. 25-Apr. 5
Aug. 1-10
Aug. 1
Lettuce, leaf Half-hardy Mar. 25-May 15
Aug. 15-Sept. 15
Muskmelon Very tender May 10-June 15 . 4
Mustard Half-hardy Apr. 1-May 10
Aug.15-Sept. 15
New Zealand spinach Tender Apr. 25-June 15 .
Okra Very tender May 10-June 15 .
Onion, from seed Hardy Mar. 25-Apr. 15 Apr. 1
Onion, from plants or sets Hardy Mar. 25-May 1 Apr. 1
Parsley Half-hardy Apr. 10-May 1 .
Peas Half-hardy Apr. 10-May 1 .
Pepper Very tender May 10-June 1 May 10 8-10
Potato Half-hardy Apr. 1-15
June 1-10
June 1
Pumpkin Very tender May 20-June 10 June 10
Radish, spring Half-hardy Apr. 5.-June 1
Aug. 20-30
Radish, winter Half-hardy Aug. 1-15 Aug. 10
Rhubarb Hardy Mar. 25-May 15 .
Rutabaga Half-hardy May 1-July 1 June 15
Spinach Hardy Mar. 25-Apr. 15
Aug. 15-30
Squash, summer Very Tender May 10-June 15 .
Squash, winter Very Tender May 20-June 1 June 1
Sweet potato Very Tender May 10-June 1 May 15 6
Tomato Very Tender May 10-June 1 May 15 5-7
Turnips Hardy Mar. 25-Apr. 15
Aug. 1-15
Aug. 1
Watermelons Very Tender May 10-June 1 . 4
  1. This classification is used to determine earliest safe date to plant vegetables. Hardy vegetables can be planted as soon as the ground can be prepared. Half-hardy vegetables can be planted as early as 2 to 3 weeks before the average date of the last 32 freeze in the spring. Tender vegetables should be planted from the time of the last average 32 freeze to one week later. Very tender crops should be planted 2 to 3 weeks after the last average 32 freeze. See Fig. 2 for average dates of last 32 degree freeze in Illinois.
  2. For southern Illinois March-June plantings can be made approximately 2 weeks earlier and July-September plantings 2 weeks later than for central Illinois. For northern Illinois March-June plantings should be about 2 weeks later and July-September plantings about 2 weeks earlier than for central Illinois.
  3. Time required to grow plants from seed before setting in field. This period will vary depending on temperature and other conditions under which plants are grown.
  4. Use plants. See page 20 for discussion on planting depths for plants.
  5. Throughout much of North America with the exception of the very hottest and coldest areas, garlic is best planted in the fall just as many of the hardy spring bulbs are. As far as timing, it should be done before the soil freezes. In most areas this planting date is sometime in late September through October. Planting at this time allows the cloves to have a chance to root and grow a shoot to the soil surface in the fall. Then in the spring, growth commences immediately when the frost goes out of the soil allowing lush growth. If planting is delayed until spring planting should be done as early as possible (March-April). This will be dependent upon whether the soil can be properly prepared. A note about spring planted garlic. Garlic from spring plantings does not come close to making quality heads of garlic as a fall planting will. Garlic planted in spring has to mature in the hotter, dryer conditions of summer thus lowering the quality quite a bit.

Transplants. Some vegetables, such as broccoli, cabbage, eggplant, pepper, sweet potato, and tomato, are usually started in the garden by means of transplants. You can buy these plants or grow them yourself indoors. Follow these directions when setting plants into the garden:

  1. Transplant if possible on a cloudy day or in the evening.
  2. Handle plants with care. About an hour before transplanting, thoroughly water plants and soil in the containers (pots, bands, flats, etc.). Roots of plants in flats should be blocked out with a knife to get as much soil as possible with each root. Carefully remove plants without disturbing the roots. Keep a ball of soil around the roots. Keep the roots moist at all times when they are out of the soil.
  3. Dig a hole large enough so that the transplanted plant sets at the same depth that was growing in the container. The only exception to this rule is if you have tall, spindly tomato plants. They can be set on an angle in a shallow trench. Cover the stem with soil roots will form along the stem.
  4. Use starter solution to get plants off to a fast start. Mix an all-soluble fertilizer high in phosphorus (e.g. 1-52-17 or 10-50-10) at the rate of approximately 1 tablespoon per gallon of water. When you transplant, place about 1 cup of the solution around the roots of each plant.
  5. Cover the roots with soil and firm the soil tightly around the plant.
  6. Protect plants from heat, wind, or cold if necessary. Plant protectors (sometimes called hot caps) made of paper or plastic are available to lessen trouble from frost in the spring. Homemade devices can be made from baskets, boxes, or jars. Do not leave the protector over the plants longer than necessary. If it gets warm during the daytime, remove the protector or open it so that the plants receive ventilation.