Strawberries are excellent fruit for the patio gardener and are especially attractive grown in special strawberry planters or tubs, producing their white flowers in late spring and delicious red fruits that ripen in summer. They can also be raised in growbags, planted in late summer to bear fruit the following year. It is possible to retain strawberry plants in growbags for two years but it is probably best if they are replaced annually.
Strawberries have white occasionally pink flowers, with pronounced yellow centers, held in clusters. They have a green, slightly hairy leaves, toothed edges with 3 leaflets per leaf. The leaves often turn brilliant red in the fall.
There are a three main types of strawberries available: June-bearing, everbearing, and day-neutral. June-bearing varieties are often recommended for short-season northern gardens; they offer a bigger summer bounty than everbearers, but plants stop fruiting after the first harvest. June-bearers will produce their crop earlier in warm climates – you could be eating berries in April.
Everbearing types, such as ‘Quinault’, produce two crops: one in June and one in September – so they aren’t really everbearing. Day-neutral types, such as ‘Tristar’, will produce from June to September, a continual but smaller crop. There are several excellent varieties of day-neutral strawberries and they are a wonderful choice for the gardener who wants a steady supply of fruit instead of having it all ripen at the same time.
Strawberries are a greedy crop. They need to be planted in well drained soil that has been well manured the previous year and do best in slightly acid soil. They also require watering in dry periods if they are to fruit properly. The yield from a strawberry plant starts to decline after the third year and plants should be replaced on a regular basis to compensate for this.
Summer-fruiting strawberries are usually divided into early, mid or late season. If there is room, then an early and a mid-season variety can be grown together; this will prolong the period when fresh fruit can be enjoyed. However, a number of varieties fruit early in their first year and then revert to mid-season.
Strawberries – shapes
Some varieties are known as perpetual fruiting strawberries. These have a small number of berries in late spring or summer, and then fruit again in the fall, when they may carry on producing over a considerable period. These strawberries succeed best in warmer areas where there is less likelihood of early frosts in the fall. Unlike the standard summer plants, the runners of perpetual fruiting varieties should be retained and the major weeding and removal of old leaves is carried out at the end of winter, just before the new growth starts.
Wild or Alpine strawberries can be planted in troughs on a patio where they make good ground-cover plants. They can also be planted in between paving slabs and are an attractive addition to a patio. They are hardier than most strawberries and prefer cool shade, they do not do well in a dry, sunny position.
Growing strawberries in tubs or barrels
This is an excellent way to produce a good crop of strawberries in a small space, but two important rules need to be observed. First, prepare the correct planting mixture, which should be equal parts by volume of sharp sand and a good quality garden compost. Make sure that the compost used contains a slow-release fertilizer, or add one if it does not.
Second, place a perforated pipe down the center of the barrel or use a specially designed container with a central watering tube. Unless this is done, the plants at the bottom of the containers will not receive sufficient water and will probably die. Plant up the barrel at the same time as it is filled with the planting mixture, pushing the plants through the holes from the inside and ensuring that the crown of each plant is level with the sides of the barrel.
Water the barrel well after planting and then do not water again for around two to three weeks – however, the plants must not be allowed to become so dry that they show signs of wilt. Less water is required when the plants are small than later when they are in full growth but too much water and likewise too much fertilizer may well just produce leaves rather than fruit.
Rotate the tubs or barrels every week so that the plants receive equal sunlight.