Planting Date

Date of planting is influenced by the cultivar, plant quality and past history of the plant. Except for the day neutral cultivars, plants should not be set before October 5. Non-dormant transplants with little foliage and/or small crowns generally develop and grow slowly and give lower fruit yields (1). If these are used, set them early in the recommended planting period for that cultivar. Generally those plants set earlier in the recommended planting period grow larger and produce more runners and fruit than those set later (11). However, if plants are set too early, especially if fall temperatures are above normal, plants may become too vegetative and fruit production may be severely delayed. If plants are set in the last week of October or later, plant growth is generally less, fruiting is delayed, and seasonal yields may be lower (11, 37). High soil fertility increases plant growth, but excessive fertility may result in oversize plants, greater daughter plant production, and possibly poor fruit quality.

Plant Spacing and Depth

Plant Spacing - Spacing of plants on the mulched beds varies with the vigor of the plant (10), and the number of rows per bed (8). On a 2-row bed, the common spacing is 12 inches between rows and between plants down the row. This spacing normally allows sufficient air circulation around plants, fairly good penetration of spray material, and enables fruit harvesting to proceed quite rapidly since fruit are more visible. With 3 and 4-row beds, the distance between rows varies from 8 to 11 inches. Most growers using more than 2 rows per bed increase the spacing between plants down the row to compensate for the decreased spacing between rows. The harvesting of fruit from beds with more than two rows per bed is more difficult, especially as the plant density increases (5, 8). As plant density increases with any row number per bed more fruit are missed by the picker and left to rot. In addition, fruit rot is also increased because fruit under the foliage stay moist longer during the day and pesticide spray coverage may be reduced (5, 8, 10).

Fruit yields can increase with increased plant density, but losses from fruit rot may lessen the advantage of increased density (10). Increased plant density also means more pesticide spray may be required to control diseases, mites, and insects. The number of rows per bed and the spacing between and down the rows is largely determined by the grower's management ability, equipment, especially spray equipment, and the quality of the crew harvesting the fruit.

Planting Depth - The diagram shown below illustrates the proper planting depth for strawberries. If plants are set too deep, the plants are unthrifty and the crowns may rot and the plants die (22, 25, 50). If planted too shallow, the root system is exposed which can result in poor rooting and shifting of the plant in breezes or when harvested (22, 25, 50). Often plants may be set at the right depth but either be in a small depression or have soil ridged around the crown. When irrigation is initiated to establish plants, the depression can fill and bury the crown or the ridge may erode and expose the roots. A firm plant bed assists in preventing the bed from settling or eroding.

Correct planting depth is important for proper rooting and to avoid plant damage or morality. A is the proper depth, while B and C are too deep and too shallow, respectively.

Bed Size

Since strawberries are shallow rooted, most of the roots are within the volume of the formed bed (22), and most of the moisture and nutrient uptake will occur within this volume. The height of the plant bed should be sufficient to permit maximum rooting and to prevent damage to roots during flooding. A bed height of 7 to 9 inches as measured from bottom of row middle is sufficient under most conditions (9). The firmness of the bed can vary greatly depending on equipment used to form the beds. The firmer beds appear to retain moisture longer, but data are not presently available on the effects of bed firmness on plant growth or yield. The width of the bed generally relates to the number of plant rows per bed. As the number of rows per bed increases, the fruit yield may increase, but the harvesting of fruit may become more difficult (8). Pesticide coverage of the more dense plant foliage may also become more difficult which may increase fruit rot. The problems become more important as plant size and density increase and as the length of the fruit stalk decreases (3,5,8). In addition, special equipment is needed for wider beds. Because wider beds cover a greater area, more plants, fertilizer, polyethylene mulch, fumigant, and pesticides are also required. Once the bed width is selected and equipment purchased to fit this bed then the opportunity to change may be limited because of equipment costs (44, 46). The potential for increased profits is greater with beds having more than 2 rows because of greater fruit yields (10). However, higher production costs and increased fruit losses because of rot may more than compensate for the greater potential fruit yields (8, 10).

Establishing Plants

Plants without adequate starch in roots require overhead sprinkler irrigation to prevent foliage loss and plant mortality. These plants will require irrigation varying from a few days to 2 weeks after transplanting (4). Initiate irrigation as soon as plants are set. Each morning start irrigation when plants show moderate wilt and continue irrigation until the hot part of the day has passed or until wilting conditions are no longer present. After a few days, irrigation can be initiated a little later in the morning and can be discontinued earlier in the afternoon. Plants should have 3 or more leaves remaining at the end of the establishment period. Excessive foliage loss delays growth and fruiting (4, 16). Dormant or partially dormant plants do not require irrigation to the extent of non-dormant plants. Irrigation for dormant or partially dormant plants is provided to cool the crowns and for moisture.

The purpose of the irrigation is to prevent the desiccation of the plant foliage until the root system can develop and absorb sufficient moisture to sustain the plant. Only a relatively small volume of water is required. However, the irrigation system generally used by the grower is designed to provide large volumes of water. This results in excessive water use and leaching of fertilizer from the plant beds. One method to reduce the amount of water applied is with intermittent irrigation. Irrigation is applied for a few minutes and then stopped for a few minutes. Control of the intervals can be obtained with time clocks and solenoids or with other devices. The following is a list of some of the practices required for the successful use of intermittent irrigation to establish plants. Some items (1, 2, 3, 4, 5, 10, 11, 13) apply for continuous irrigation also.