It is very possible - even easy, given some basic knowledge - to harvest your own fresh, delectable strawberries all the year round. Most of the requirements needed would already be present in the repertoire of even the most weekend gardener. The secret is in selection of variety and treatment. These days the modern strawberry cultivar has been bred to already cover the absolutely longest season possible; with a little encouragement the home gardener can encourage them even further so that they cover the entire calendar year. With the current eye-watering price of strawberries in the shops, and the incentive of harvesting your own plump, juicy and sweet berries - even on Christmas Day, there can be little excuse not to start your own serious strawberry growing programme. Here follows a calendar of strawberry growing throughout the year.
For harvesting in April Grow naturally early varieties such as Gorella, Cambridge Vigour, Honeyoye and Elvira in pots or growbags, bringing them into the cool greenhouse or conservatory in February. Little heat would be required to encourage the berries to form and ripen during April, just a few weeks ahead of their natural season. The varieties mentioned above are well suited to production under cover and also take readily to container growing. They should have been planted in their containers the Autumn previously so that they are well established beforfe being brought in for forcing.
For harvesting in May Early varieties like Rosie, Honeyoye, Cambridge Vigour and Emily can be grown outside as you would normally; cloche the plants just as the flowers begin to set and the season will be advanced naturally. Watch out for mildew and other fungal diseases which can sometimes proliferate under cloches and provide vebntilation during the middle part of the day where possible.
For harvesting June/July This is the strawberries natural season in the garden and the period of greatest natural abundance. By planting a selection of early, mid and late season varieties several weeks of strawberry harvesting can be obtained with no special treatment at all. All varieties have their own special merits; if asked to recommend a planting programme we would select the following: For early season - early Mid June - Honeyoye, Rosie or Gorella. For the mid season - which will ripen second half of June - Eros and Red Gauntlet. And for the lates - ripening into July - Rhapsody without question.
For harvesting August-October Here the perpetual or Autumn fruiting varieties really come into their own. They will start to produce their first flushes outside, with no encouragement, in late July and will then go on at intervals right through to the frosts; this can be extended still further by cloching as frosts threaten, into November some years. There are several very good varieties to choose from, our own favourites are Aromel, Rabunda and Flamenco. The Autumn fruiting or perpetual cultivars use a lot of energy, adequate feeding provides the best results.
For harvesting October-March. A small greenhouse with just mild heat can be home to the invaluable Day neutral strawberries. These differ from the aforementioned Autumn fruiting or perpetuals in that, as the name suggests, they are entirely oblivious to Day length and season. Therefore if the temperature for them is kept above say 12 degrees, they will be initiated into flower and fruit. It should be noted that you can bring an Autumn fruiting variety into the greenhouse and once its finished its finished; no matter how much heat you give it, it won't be fooled into thinking it's summertime because it 'knows' the daylength is too short. Not so with the Day neutrals. This means that the average greenhouse is an ideal home for this group in the winter and they will flower and fruit at intervals right through until Spring! The best variety is Seascape, or perhaps Selva. Then, in the Spring the plants can be planted out into garden or allotment and after a short rest they will then provide a further harvest over several weeks during the Summer. Day Neutrals do not produce fruits of flavour and texture comparable to the best normal varieties. The texture is denser and not as juicy; however they certainly compare favourably to the average supermarket strawberries and are very good for 'out of season' fruits.
Some points to remember. Strawberries in containers of any kind should only be cropped the once. However they can be planted at a greater density than you would in a traditional strawberry bed; a 12" pot can happily take 5, or a standard growbag 5 or 6. Additional feed such as seaweed extract gives vastly improved results. Strawberries grown under cover benefit from hand pollination with a feather or soft haired brush - because there aren't enough insects around to do the job for you. Remember adequate watering is very important - not just for the plants natural health but also the eating quality of berries; if the plants go short of water at a crucial time such as when the fruits are swelling, they may in turn be dry. All other cultivation hints and requirements are as detailed for strawberries in our main cultural guide.
The modern strawberry is a versatile and accommodating crop indeed. I hope the above encourages you to plan an extended cropping programme of your own. It isn't difficult to achieve very worthwhile results.