Cultivation

Growing strawberries in your home garden can be an interesting and rewarding experience. By growing various cultivars (varieties) of strawberry, you can pick ripe fruit from late spring until frost in the fall. If you care for plants properly, you can obtain enough berries for your family from a relatively small area.

SELECTING A SITE

Strawberries require direct, full sunlight for best production. They bloom early in the spring, so don't plant them in frost pockets-low-lying areas in which cold air drains or areas (surrounded by tall trees, for example) where cold air is trapped.

Avoid planting where tomatoes, peppers, potatoes, eggplant, strawberries, raspberries, or black berries have grown in the past 3 years. These plants can all act as hosts for fungi, such as Verticillium wilt, and insect pests that build up in the soil unless you place these crops on at least a 3-year rotation schedule.

Strawberry plantings can remain productive for 3 to 4 fruiting years. You can minimize the buildup of many insect and disease problems by rotating the strawberry patch from one site to another each time you make a new planting.

Soils. A well-drained loam soil, high in organic matter, is ideal. Avoid planting in heavy clay soils. If your soil is sandy, pay more careful attention to watering and fertilization. However, strawberries will tolerate a wide range of soil types if you properly modify the soil. You can improve most garden soils by adding organic matter.

The soil should be well-drained -- strawberries can't tolerate standing water or "wet feet". If the only soil you have available has poor drainage, you may be able to improve it by tilling and adding organic matter.

Planting on ridges or raised beds also helps if soils drain poorly (see "Preparing the soil" and "Planting systems").

SELECTING A CULTIVAR

Strawberry cultivars are normally placed in one of three categories (or types), based on their responses to day length (photoperiod) and the season in which they produce a crop: June-bearers, everbearers, and day-neutrals.

June-bearers produce one crop a year, usually from early June to July. These plants produce flowers, fruits and runners (daughter plants produced on aboveground stems) in sequence. Most commercial plantings are of June-bearing cultivars.

Everbearing types produce two crops a year, one in June and one in the fall. Everbearers usually produce few runners.

Day-neutrals produce a relatively continuous crop throughout the growing season.

The fruit of everbearers and day-neutrals is typically smaller, and total seasonal yields are often lower, than that of June-bearers. However, the advantage in growing these types along with the June-bearers is that you can harvest fruit for most of the growing season.

ESTABLISHING YOUR PLANTING

Preparing the soil. A good supply of organic matter in the soil improves aeration and drainage, and increases water-holding capacity. You can apply organic matter the summer or fall of the year before you plant; manure applied at 2 to 3 bushels per 100 ft2 is a good source.

You can also use compost, leaves, chopped hay or straw, peat moss, sawdust, etc. Take care to use only materials that you think are free of insects and weed seeds.

Dig, plow, or rototill the material into the soil to ensure that it will be well decomposed (rotted) by planting time the following spring. If you incorporate large amounts of non-decomposed (fresh) material into the soil, add ammonium nitrate (33% nitrogen) at 1 lb per 100 ft2 to aid in decomposition.

Eliminate all perennial weeds the year before you plant. Don't let weeds go to seed!

The site you select and prepare should drain well. However, if drainage is poor, you can form ridges or raised beds. Mix organic matter, coarse sand, and fertilizer (see below) with the soil. Shape ridges or raised beds 8 to 10 inches high.

Make ridges wide enough to grow a single row of plants; raised beds should be wide enough to accommodate double-or-triple wide rows in the hill system (see "Planting systems").

Planting. When you plant or replant strawberries, begin with certified disease-free plants purchased from a reputable nursery. Avoid using runner plants from an old established patch-they're often diseased. Strawberries are subject to several virus diseases that are transmitted to the new runner plants, mainly by aphids.

Purchase plants just before planting. If you can't plant right away, store plants for a short period in a closed plastic bag in the refrigerator (34 to 40°F), or you can temporarily heel them into the soil.

To "heel in" plants, dig a shallow trench that's deep enough for the roots. Place plants in a single layer against one side of the trench with crowns (short stem of the strawberry plant) partially above the soil line. Cover roots with soil and gently firm it in place. Water the soil.

Keep plants moist before you plant, and plant in a damp, well-tilled soil. Don't leave plastic bags containing plants in the sun. If possible, plant on a cool, cloudy day.

Plant strawberries in early spring, as soon as you can prepare the soil. Use a spade, shovel, or trowel to set the plants. Dig a hole for each plant large enough to place the roots straight downward but somewhat spread. The midpoint of the crown should be level with the soil surface; the top most root should be just below the soil surface (figure 1).

If you set plants too high, the roots may dry out. If you set them too low (figure 1), the growing tip at the top of the crown may smother and rot. Fill the hole with soil and press firmly around the roots - take care that no air pockets remain. Irrigate the plants as soon as you set them.

Planting systems. The matted-row and hill systems are the most common training methods for strawberries. The hill system is preferred for everbearers and day-neutrals, because the don't produce as many runners as June-bearers. June-bearers are usually grown in a matted row, but you can also grow them in a hill system.

In the matted-row system, set plants 18 to 24 inches apart in the row (or raised bed), with 3 to 4 feet between rows (figure 2). Allow the runners that form from the "mother" plants to develop and root - they'll form a matted row 18 inches wide. Keep the remaining 1.5 to 2.5 feet between rows clear by sweeping early-formed runners into the row or by cutting off late-formed runners that grow into the aisle or off the edge of the raised bed.

The hill system is ideal for cultivars that produce few runners, such as everbearers. Set plants 12 to 15 inches apart in double- or triple-wide rows (on raised beds if necessary). Aisles should be 1.5 to 2 feet wide (figure 3). Remove all runners that develop throughout the growing season before they root.

WHAT PLANTING SYSTEM SHOULD YOU CHOOSE?

  In the matted row, the runners produced are allowed to fill in a space 18 inches wide.

  In the hill system, you must remove all runners that are produced.

  Grow everbearers and day-neutrals in a hill system, as these types produce few runners and won't form a nice matted row. You can grow June-bearers in either system.

Matted row versus hill system

  The matted row requires less labor to maintain and is productive. However, if you let the row get too dense, diseases such as fruit rot may become more of a problem and fruit size will be smaller.

  The hill system can produce both high yields and large fruit, provided you diligently remove all runners that are produced before they root. The plants will branch and become very productive.

FIRST SEASON'S CARE

Blossom removal. In June-bearers, remove all flower clusters during the planting year before fruit is formed. Be patient! If you try to produce strawberries during the planting year of June-bearers, you'll stress the young plant. This limits crown and leaf growth, which will decrease the yield you get the following season.

In everbearers and day-neutrals, remove only the first flush of flowers, allowing flower clusters formed after July 1 to develop fruit. This allows plants to get well established before fruiting.

Runner removal. Cut off all runners every 2 to 3 weeks from plants growing in the hill system. In the matted-row system, the majority of the following season's crop will come from the mother plants plus runners that develop and root before August.

Ideally, you should position runner plants as they develop to attain a density of about 5 runner plants per square foot of matted row. Place a small amount of soil just behind a runner plant to keep it in place. Once you achieve this density, remove all other runners. (This is quite labor-intensive.)

Another method is simply to remove all unrooted runners from the matted row from September 1 through the fall, when runner production ceases. Matted rows that are too dense produce lower yields of smaller berries, have a larger proportion of misshapen berries, and have a higher incidence of disease.

Cultivation and weed control. Weeds compete with the shallow-rooted strawberry plant for water and nutrients, and they often harbor insects and diseases. Hoe around the plants often enough to destroy weeds and to keep the soil loose. This promotes good growth and permits runner plants to root quickly when establishing the matted row.

Check with your county office of the Agriculture Commissioner or a local garden supply store for herbicides registered for use on strawberries in home gardens.

You can use sawdust, bark, or black plastic mulch in the row to keep down weeds, conserve moisture, and keep fruit clean. However, mulches may lead to an increase in slugs.

Mulch is particularly useful for hill-system plantings. Avoid covering the top of the crown or growing point of plants with sawdust or bark mulch. Black plastic is very useful. Clear plastic isn't as suitable - weeds grow underneath it.

You can apply plastic most easily just before or just after planting. Before planting, place the plastic over the planting area or raised bed. Edges of plastic should overlap and be held down with soil. Cut circles with a diameter of 6 inches in the plastic where you'll set the plants. Plant through these holes.

If you lay plastic just after you plant, feel for the plants under the plastic and carefully cut holes around them. The holes cut in the plastic do allow some weeds to grow around the plants, but they're necessary to ensure that plants get enough water and for fertilization.

You can place a thin layer of bark mulch on the plastic to make the planting look more attractive. Runner plants can't root through the plastic, but you should still cut them off plants growing in the hill system.

CHECKLIST FOR ESTABLISHING YOUR PLANTING AND CARE IN THE FIRST YEAR:

  Choose a good site.

  Eliminate all perennial weeds.

  Choose a cultivar(s) suitable for your needs.

  Choose a planting system.

  Prepare the soil by adding organic matter and forming raised beds, if necessary.

  Apply fertilizer.

  Till the soil.

  Purchase certified disease-free plants.

  Plant in the spring.

  Set plants to the correct depth.

  Remove all flower clusters from June-bearers and the first flush of flowers from everbearers and day-neutrals.

  In the hill system, remove all runners as the form.

  In the matted row, train runners to the row (18 inches wide); remove all runners that form after September 1.

  Irrigate as required.

NOVEL GROWING METHODS

You can also plant strawberries in barrels, planters, or hanging baskets. These planting will require close care in watering, fertilizing, and other cultural requirements. You may find fruit production in hanging baskets disappointing.

Everbearing or day-neutral types are best suited for container production. The containers you choose should be well-drained. A possible soil mixture consists of 1 part sand, 1 part peat moss, and 2 parts garden soil. You can replace the peat moss with well-rotted manure or compost. Mix about ½ cup of complete fertilizer, such and 10-20-20, into each bushel of the growing medium.

HARVEST

Pick fruit every other day or daily during hot weather. Fruit harvested in the morning usually has a longer shelf life. Pick all ripe berries - fruit left on the plant become overripe, which promotes development of disease and insect problems. You can refrigerate fruit for several days. Avoid washing fruit until just before you use it, to prevent softening and decay.

PESTS

If any diseases or insect pests become a problem - such as weevils or aphids - check with your county office of the Agriculture Commissioner for control recommendations. The incidence and spread of fruit rot may be decreased by preventing a matted row planting from becoming too dense and by picking and discarding infected fruit.

For varieties best suited for the home gardener see