Growing strawberries organically
Growing strawberries organically is one of my favourite activities in the food garden. Strawberries are a wonderfully nutritious and sweet tasting fruiting vegetable. I enhance organic methods with biodynamic soil and plant preparations.
One of my previous food gardens about 5 years ago had about 1000 strawberry plants. I am incorporating strawberries into our new food garden in Draper and have already planted out 50 strawberry runners to get it underway. They multiply fast!
Here are my tips on growing strawberries organically.
Its best to locate the strawberry patch in full sun. Fruiting crops need a lot more sun than root or leaf crops, so don’t plant your strawberries in a shady corner. If you do not have any garden space and only have pots on a balcony, then make sure you can move the pots around so they get the most sun.
My layout suggestions relate mostly to a garden bed space rather than using pots, though strawberries, being a relatively shallow rooted plant can grow reasonably well in pots, but in my experience growing them in soil in a garden bed will always produce better results. Its ideal to create raised rows so you can walk between the rows to manage the plants and harvest. Ensure you have good drainage in your patch.
Strawberries prefer soil which tends more to sandy rather than dark rich loamy soil. If your soil has a lot of clay, then add river sand to it. If your soil is too rich, then you will get a lot of leaf growth and not so much flowering and fruiting.The sandy soil has a higher proportion of silica and this helps a lot with a flowering fruiting crop like strawberries.
When I clear beds each year, I condition the soil by giving them some finely crushed basalt, hard wood ash, liquid manure using cow manure or comfrey tea (both enhanced with biodynamic compost preparations) and biodynamic soil activator (this is especially important when planting the runners as it contributes to healthy root and leaf development).
Watering and drainage
When you plant out runners, keep soil moist until runners set well and then slow down watering until they start flowering. Once fruit comes on, increase watering. If you are growing in pots or containers, they will need more water as these tend to dry out faster than being in the ground. Be sure to design your patch so it drains well.
On a new bed, its best to condition the soil first, then place a light mulch, make holes in the mulch, insert a handful of good compost (if you have it) and plant the strawberry runners. In our sub tropical climate the best time to plant is April and plants fruit through the cooler months into spring. In more temperate climates, plant after frost in early spring and plants fruit through to mid summer. I always plant on a planetary sign of fire (fruit).
Its important to keep some distance between plants as airflow is vital for healthy cropping. I plant the strawberries in a square pattern with one plant to each corner and about 40 cm between plants on an 80cm bed, thus each plant is 20cm in from bed edge.
The ideal companions to use are from the onion family as these detract slugs and grow at the same time as the strawberries go from the leafy stage into their fruiting cycle. I use spring onions, red onions and leeks and plant them in the middle of the square planting pattern.
Propagating your strawberry runners
Strawberries send out runners after they have fruited. This starts with a long tail coming off the main plant and as it moves along the ground, new plants begin to form on the tail (runner). Each plant may have 3 – 4 runners and each runner could have 2-3 plants. If you leave your patch as it is after a few crops, you begin to have a very dense patch.
Its important to dig up the new runners after fruiting has finished on the older plants and move the new runners to your next beds or give them to friends. In our sub tropical climate, I do this in early April, even though they have finished fruiting in November. This is because the runners multiply over our warm wet season from late December to late March
You will find that by giving your strawberries more space and not letting them get too dense, they will fruit more. In addition, the newest plants, ie the runners will normally produce the biggest strawberries.
After 3 crops of growing strawberries organically with your original strawberry plants, pull them up and put them in your compost and replant new runners in their space (be sure to tune your soil before doing this). You will have plenty of runners if your patch is going well.
To give you an example, I started one of our patches with 12 runners. Over 3 years it multiplied to at least 1000 plants in the patch that I managed. After 4 years I could also supply 1000’s of spare runners to many people in my local area.
Keeping up productivity
Make sure you water the plants well when they are fruiting. Keep your eyes open for slugs and pick your strawberries when they are ready, as the slugs will be more attracted by over-ripe strawberries. Your onion family companion plants will help a lot with slugs.
Follow the propagation rotation described above and give the plants some space. Once the strawberries start flowering, I use biodynamic preparation 501, which is silica, as this enhances flowering and fruiting, nutritive quality and disease resistance (especially from fungus).
Chemically grown strawberries are heavily sprayed for fungus reduction. You can completely avoid these chemicals with growing strawberries organically and supporting this with biodynamic soil and plant preparations described above.
Accept that some birds will eat the strawberries and if the birds really are a big problem, you may need to resort to netting. We used to do that until we started using biodynamic preparations on our whole block and the birds leave them alone now.
My strawberry patches has never been treated with pesticides, herbicides or artificial fertilisers.
Mulching your beds quite heavily is very helpful before you plant the strawberries. Since they grow over a long period, you will need to keep on top of the weeds. I also mulch in paths. Some gardeners use pine needles as mulch since their acidic nature is beneficial for strawberries. If these are hard to get, I tend to use grassy hay or sugar cane mulch.
Its best to harvest the strawberries in the morning when they have taken in the dew of the evening. In my experience, they tend to turn red at night, quite strange really.
Enjoy your strawberries and share your runners! Check out our new strawberry patch at our July 20-21 two day biodynamic workshop in Brisbane. Hopefully they will be ready to harvest by then.
Authored by Peter Kearney: My Food Garden