There are a number of varieties available that do well here in Whanganui.
Strawberry varieties fall into two main categories - short-day varieties and day-neutral varieties. The biggest difference is 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. I have been harvesting fruit throughout the summer with a mixture of both types of plants and harvested my last bowlful only two weeks ago in late April. The first ones were ready in October last year.
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. In some seasons, as the days shorten in autumn, flowering is also initiated and small crops may be produced. Camarosa is a short-day variety which produces large, well-flavoured fruit right around Christmas. It is a real winner. Another is Ventana.
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. Day-neutral varieties include Monterey, Aromas, Albion and Cabrillo.
Two top strawberry varieties: Camarosa will be available as bare root bundles for a very limited time. The Camerosa varieties are in-store now. Monterey varieties are due in the next week or so. This is the most economical way to buy strawberry plants. Otherwise, all the mentioned varieties will be available from late May or early June in pots and punnets.
While strawberry plantings can be made year-round, planting done in the cooler months tends to result in heavier cropping than plantings made in warmer months. If they are planted too late, i.e. closer to the longest day (in December), they will tend to produce an abundance of runners instead of fruit.
Where to grow
There seems no limit to how and where strawberries can be grown, and they are fairly foolproof, so anyone can plant them and be rewarded with fruit.
They can be grown in old car tyres, where the heat of the tyres hastens ripening. This method keeps the fruit off the ground and therefore clean from soil. They can be grown in hydroponics, in glazed or terracotta pots or specialist herb/strawberry planters. They are an edible option to grow in a hanging basket, or they can fit in the herb garden. Some people grow them along the edge of a vegetable garden and others will dedicate a spot to use to mass-produce their favourite berry.
Many grow strawberries in pots and containers of various forms. If you are planting strawberries in pots, make sure you should use a specialist mix such as Tui Strawberry Mix – as with the success of most plants, the quality of the media they grow in plays a significant role in their success.
The biggest factor in growing good strawberries is site selection. The plants need a sunny position and well-drained soil that has a good structure. When planting strawberries, improve the garden with the addition of Tui Strawberry Mix or Tui Sheep Pellets. These will work to improve soil structure and add nutrients as well as bulk up the soil to 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 will also help to keep the fruit clean. Suitable mulches include straw, sawdust, pine needles, pine bark or wood shavings.
The traditional and very effective method of growing strawberries is to cover the raised mound with black polythene plastic or a weed mat, making a small slit for each plant. The black mulch attracts heat, increasing soil temperature, making fruiting earlier and keeping the fruit clean from dirt.
Cultural notes
Strawberry plants will produce significantly more fruit if they are watered and fertilised regularly. Like with many plants, you can buy a specially blended fertiliser for them 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 the next year’s fruit production if these are removed before growing too much, as they will drain the plant of energy that will benefit the next season’s fruit. However, in the second and third seasons, 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; just keep an eye out for slugs during spring which may eat the new leaves, and the occurrence of aphids and mites during the summer months, which may require control using bee-friendly Yates Mavrik.
Bird control
Planting strawberry plants (like other fruit trees) is, ironically, a great way to attract birds into the garden. So, to enjoy the fruits of your labour, bird control is essential when growing strawberries, and it seems 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 30 centimetres above the plants so when birds sit on the cloth, they are not able to reach through the netting and eat those precious berries.
The netting also needs to be secured around the base to prevent side entry by the birds; the use of bricks or something similar to weigh down netting so it stays on the the ground is effective.
There are a number of different frame options, from bending number eight wire or steel into hoops to making a ‘square’ frame with garden stakes, to putting an upturned pot on the top of a stake, which keeps the netting held up away from the plants.
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.
Gareth Carter is the general manager of Springvale Garden Centre.