Strawberries are quick to give results - if planted at the start of spring, you can harvest fruit from mid-November into the summer months, writes Gareth Carter.
Gareth Carter is the general manager of Springvale Garden Centre in Whanganui.
OPINION
Some warmer weather, albeit windy and unsettled, appropriately typifies the official start of spring. It is a great time to plant, with moist soil conditions and warming temperatures promoting good plant growth.
The warmer temperatures can lead us to think of summer and the delicious berries that ripen during those months. Berries are a prized treat by many people. They are healthy and delicious, and often can be expensive to buy in the supermarket. Being small and soft they are time-consuming to harvest commercially which contributes to making them expensive. However, berries are easy to grow in the home garden.
Growing berries at home can be achieved in a garden of any size. The growth habit of berries is smaller than that of many fruit trees - this makes them well-suited to growing in pots and containers.
What is referred to as berries is diverse in itself. The most popular berries to grow include blueberries, strawberries, raspberries, boysenberries and thornless blackberries. Lesser known but still popular are the gooseberry, mulberry and elderberry.
Strawberries are the focus of today’s column. Strawberries are quick to give results - if planted now, you can harvest fruit from mid-November into the summer months.
Strawberries certainly fit into any size garden and grow well in pots and containers. If you are planting strawberries in pots, make sure you use a specialty potting mix such as Tui Strawberry Mix or a top-quality potting mix such as Ican Premium Potting Mix.
The biggest factor in 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, Tui Sheep Pellets, Yates Dynamic Lifter or Tui Strawberry Mix will help improve soil structure and bulking up the soil can give height to the bed that will aid in good drainage.
Strawberry varieties fall into two main categories: short day varieties and day neutral varieties. The biggest difference is that the fruiting peak falls at a different time so if you plant a mixture of these varieties, you will be harvesting fruit for longer.
Short day varieties initiate flowering when, as the name suggests, the days are short in winter and spring. 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 crops may be produced. Camerosa and Ventana are good short day varieties.
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. Monterey, Albion and Aromas are good day neutral varieties.
While strawberry plantings can be made year-round, planting in the cooler months tends to result in heavier cropping than plantings done in warmer months. If they are planted too late, closer to the longest day in December, they will tend to produce an abundance of runners instead of fruit.
Having a short-day variety growing will give an early crop from October to January. From December to March, Monterey, Albion and Aromas, the day neutral varieties, should be fruiting. Having both short and day neutral varieties will give six months of strawberry harvesting.
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 to make fruiting earlier and keeping the fruit clean from dirt.
Strawberry plants will produce significantly more fruit if watered regularly and fertilised with a specially blended fertiliser such as Ican Berry Food.
Strawberry plants will produce good crops for three years after which 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 subsequent year’s fruit production if these runners are removed before they grow 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 be fertilised in August or early September.
Strawberries are relatively pest-free but during spring keep an eye out for slugs that may eat the new leaves.
Bird control
Bird control is essential when growing strawberries and it seems that this is where many people come unstuck. The most effective method is to construct a frame on which bird netting can 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 to eat our yummy berries.
The netting needs to be secured around the base to prevent side entry by birds. Using bricks or similar to weight the netting to the ground is effective.
There are different frame options, ranging 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, plant more.
For more gardening information visit www.springvalegardencentre.co.nz.