How to Grow Pesticide-Free Strawberries in Your Greenhouse
I was just reading about how over-sprayed commercial strawberries area. I was reading this on the same day I was planting up my own greenhouse strawberries!
Why Grow Strawberries in Your Greenhouse?
It is always a good time to have a home greenhouse but when you calculate the luxury of growing your own pesticide-free strawberries, it feels like a bonus. I am using a little trick I tried last year on my outdoor fence. Greenhouse strawberries in rain gutters. The added bonus? They will be planted in my greenhouse so the nearly-dead bare-root plants starting to show up at hardware stores and garden centers have met their match. They will spring to life in your greenhouse.
What You Need to Grow Strawberries in a Greenhouse
Why not try growing berries? STRAWBERRIES. Apparently, in North America, we each eat about 8 lbs of strawberries a year and the Environmental Working Group lists them as number one on their Dirty Dozen list of edibles.
With a little forethought, you can grow your own berries. Here is what you need:
- Some kind of a greenhouse that you can attach gutters to
- 1 piece of 10-foot long rain gutter plus 2 end caps
- Plain 6" Aluminum brackets
- 20 bare-root or potted da neutral strawberry plants (these are seasonally coming into nurseries and greenhouses in 4" pots or in dormant packs of 10 inn a cardboard sleeve)
- Soil-less planting mix
- Alfalfa feed or other slow-release fertilizer
Planting Strawberries in Rain Gutters in a Greenhouse
Start with your greenhouse
- If your greenhouse is less than ten feet long you can cut the standard 10' long rain gutters to fit with tin snips if necessary.
- If you are cutting your gutters you might decide to stack them vertically to fill a whole greenhouse wall. I left a foot (30 cm) between each section of the gutter.
- Drill holes in the bottom of the gutter every 12 inches (30 cm) to allow drainage.
- Using the built-in groove in your greenhouse frames install the same screws you would use to mount a shelf or hanging basket. I attached three brackets for each ten foot length of rain gutter.
Plant your Strawberries
Purchase bareroot strawberries
I bought mine from a favourite nursery who ordered them on my behalf from a wholesaler. They are also available are dormant plants from hardware stores and smaller garden shops as spring comes to your region. For each ten-foot piece of gutter buy 20 plants because they are planted 6 inches or 15 cm apart.
Fill the gutters
Use a soft soilless mix such as Promix BX.
Trim the roots
Trim the roots on the greenhouse strawberries leaving about 2-3 inches (5-7 cm) of root on each plant. Push these roots into the soft soil about 6 inches or 15 cm apart, making sure the crown is right at the soil level and not below and not above.
Water thoroughly and sprinkle lightly with compressed alfalfa pellets sold as guinea pig food or at feed stores as fertilizer. Alfalfa should cover no more than 50% of the soil surface because the pellets expand as they absorb moisture.
You can also use an organic fertilizer like Acti-sol placed in small mounds between plants.
Wait and watch
Trim off any flowers or runners that form before the leaves are so large enough so they are touching the plants next to them. I expect this will take about a month to 6-weeks.
Let is bloom
When plants are touching let blooms flower but keep cutting off the runners. If runners are left in place you will get fewer flowers. Berries will form by spring and be edible a month or two before your friends are eating from their outside gardens.
Pick your berries
Finally, invite your friends over for a strawberry shortcake and give them a tour of your greenhouse. I wish everyone I knew had a greenhouse. Meanwhile, I share and grow the food I am excited to eat.
P.S. If you can't find plants at the store you can chip some out of the ice in your garden and when they warm up divide them in your greenhouse. Trim roots and plant them as described above.
Tips for Growing and Harvesting Strawberries in a Greenhouse
If all the plants in your garden are June-bearing plants, they will all bloom at once and then your rain gutters will be all leaves with no berries for the rest of the season. This is no good. For a longer bloom and berry season, find strawberries described as day-neutral with names like Hecker, Albion, Eversweet, Tristar, Quinault, and Fort Laramie. The total harvest might be the same as your old-fashioned June bearing strawberries but the harvest will be spread out from June until November.
Water sparingly at first and then as often as daily. I installed a drip tape and timer on my outdoor berries in rain gutters last year and they were evenly moist and produced berries all summer and into November when they froze.
I have had aphids on my plants in the past but a simple phone call and help arrived. I buy little insects to parasitize aphids quickly and harmlessly called aphidoletes.
No need to spray and spoil your perfectly clean fruit with insecticides like all the commercially sold berries. Good for you and good to eat.
Sneaky idea: we set the rain gutters on the brackets in our greenhouse but did not attach them to the brackets. We might decide to move the berries outside in summer when our tomatoes in the greenhouse beds get big and start shading the berries. We have brackets outside on our fence from our trial project last year so we might add more brackets 30 cm below the existing ones and move the greenhouse gutters outside in the heat of the summer.
More from Donna
For more great tips from Donna, visit www.donnabalzer.com.
You can also read Donna’s gardening books: No Guff Vegetable Gardening with Steven Biggs and her just released Gardener’s Gratitude Journal: Part Diary, Part Personal Growing Guide.