Spring is now officially here and there is lots to do in the garden. Lawns, vegetables, flowers and weeds all have something happening with the change of season. I am enjoying getting home from work and finding it's still light outside. I think this is one of my favourite times of day in the garden and I certainly miss it during the winter months.
One of the staples that I grow in my garden every year are strawberries. Strawberries are one of the easiest plants to grow. They will fit into any size garden and also grow well in pots and containers. They are quick to give results. If they are planted now, you can be harvesting fruit from mid-November and through into the summer months.
I have grown a number of different varieties over the years and like to have a mix of the short-day type and the day-neutral type (explained below). I have really found strawberry Camerosa as the best performing short day type but have moved through a few varieties of the day-neutral type. Last season, with considerable success I trialled a handful of the variety Albion and I have now planted a bed of 25 plants of these for this season.
Strawberry varieties fall into two main categories; short-day varieties and day-neutral varieties. The biggest difference being that the fruiting peak falls at a different time, so if you plant a mixture of these varieties you will be harvesting fruit for a longer period.
Short-day varieties initiate flowering when as the name suggests the days are short in winter and spring. Subsequently, the bulk of the fruit of these varieties will start in early November, mostly finishing after Christmas. As the days shorten in autumn, flowering is also initiated and small crop may be produced. Camerosa is a good short day variety.
Day-neutral varieties, in contrast, will fruit any time of the year when the temperatures are warm enough for growth. These varieties tend not to have such a large flush of fruit at once but produce consistently for a longer period. Aromas is a good producing day-neutral variety for Whanganui.
While strawberry plantings can be made year-round, planting done in the cooler months tends to result in heavier cropping that plantings made in warmer months. If they are planted too late, ie. closer to the longest day (December), they will tend to produce an abundance of runners instead of fruit.
The two varieties that I talked about earlier do well here in Whanganui. Having both Camerosa and Albion growing should give me an early crop from October to January of Camerosa. Then from December to March, Albion should be fruiting – assuming that we have a good summer!
Where to grow
There seems no limit to how and where strawberries can be grown, and they are fairly fool-proof that anyone can plant them and be rewarded with fruit! Many will grow strawberries in pots and containers of various forms. If you are planting strawberries in pots make sure you should use a specialty potting mix such as Tui Strawberry Mix. The biggest factor to growing good strawberries is site selection. The plants need a sunny position and a well-drained soil that has good structure. When planting strawberries in the garden the addition of compost or broken down animal manure will help improve soil structure and by bulking up the soil can give height that will aid in good drainage.
Mulching and feeding
Mulching the soil surface between plants will prevent weeds, maintain an even soil temperature and prevent moisture loss in summer. A mulch such as pea straw will also help to keep the fruit clean. The traditional and very effective method of growing strawberries is to cover the raised mound with black polythene plastic or weed mat making a small slit for each plant. The black mulch attracts heat increasing soil temperature making fruiting earlier and the fruit clean from dirt.
Strawberry plants will produce significantly more fruit if they are watered and fertilised regularly. Like many plants, you can buy a specially blended fertiliser such as Tui Strawberry food which is blended with the appropriate proportions of NPK and trace elements. While they like to be well-drained, plants will need to be watered during the summer months. This is best done in the early morning to reduce the risk of humidity build-up.
Strawberry plants will produce good crops for three years after which time the mother plants are best thrown out. The plants will generally produce runners each season during late summer. In the first year, it is beneficial for fruit production of the subsequent year if these runners are removed before they grow too much as they will drain the plant of energy that will benefit next season's fruit. However, in the second and third season, saving some runners and replanting will allow you to replenish or enlarge your strawberry patch.
For plants that are starting their second or third season all the dead leaves from the previous season should be pruned off and removed during winter. This helps minimise the hosting of pests and diseases. Plants should then be fertilised in August or early September.
Strawberries are relatively pest-free though keep an eye out for slugs during spring which may eat the new leaves.
Bird control is essential when growing strawberries and it seems that this is the area where many people come unstuck. The most effective method is to construct a frame on which bird netting may be draped. The frame needs to be able to hold the bird netting at least 30cm above the plants so when birds sit on the cloth they are not able to reach through the netting and eat those precious morsels.
The netting also needs to be secured around the base to prevent side entry from the birds, the use of bricks or similar weighting netting to the ground is effective.
There are a number of different frame options from bending number 8 wire or steel into hoops, to making a square frame with garden stakes.
How many to plant? A rule of thumb is to plant five plants for each family member. If you want to eat bowlfuls of strawberries every night during summer then plant more!
Have a good week!
Gareth Carter is general manager of Springvale Garden Centre