Strawberry propagation, Heritage Harvest Festival

 

 

GFM-September 2013-cover-300pxThe September issue of Growing for Market is out. For this issue I wrote about our efforts to find a sustainable method of growing strawberries. We now use landscape fabric with holes melted in it, and keep the plants for two years. We are rebuilding after some years when the weeds overcame our previous beds, which had organic mulch (newspaper and hay). Our plan is to have two patches, and till in the two-year old one after harvest (after removing the landscape fabric and drip tape of course!), and make one new patch each summer. We’re a bit late this summer, but the system has promise, and I am optimistic!

Our new strawberry bed, using landscape fabric.  Credit Wren Vile

Our new strawberry bed, using landscape fabric.
Credit Wren Vile

In the past we have tried buying dormant plants in the spring (disadvantage: needing to weed the plants the first year and getting no fruit until the following year); buying plugs in fall (disadvantage: expensive) and various methods of propagating our own plants (mixed results).

We have tried keeping the plants for four years (disadvantage: way too much weeding); keeping the plants for two years (better); and accidentally keeping the plants for one year only (disadvantage: expensive).

We have tried organic mulch (disadvantage: lots of weeding); black plastic (disadvantage: unsustainable use of fossil fuels, and disposal was a pain); and now – landscape fabric. You can read all about how we do that in GfM.

As for the various methods of propagation, our current favorite is to grow our own plug plants from runner tips, using a home-built mister/fogger system. Our traditional method of propagating was to prepare new beds in late summer, then dig up runners from the paths or beds of the established plants and move them directly to the new beds. Success with these “Fresh Dug” plants relies on two weeks of intensive watering after planting. We also tried a method that worked well for me in England – pegging runners (still attached to the mother plants) down into small pots of soil for a few weeks until they had rooted, then snipping them from their mother plants and setting out a new bed. This works in rainy climates, or with overhead irrigation, but it didn’t work for us once we switched to drip irrigation. What a lot of trial and error!

New strawberry plants popped into the holes in the landscape fabric. Credit Wren Vile

New strawberry plants popped into the holes in the landscape fabric.
Credit Wren Vile

In my article, I mentioned cutting “runner tips.”  These are small unrooted runners, that need potting up and keeping alive for 4-6 weeks to grow into plugs. Here are instructions for the 6-8 week method we use when we propagate our own plants:

  • July 1-7: Fill 50-cell plug flats with screened compost. Water to activate the soil
  • July 8-14: Harvest runner tips or young runners, using pruners. Clip with ½” of the runner attached, to act as an anchor for the young plant. Choose runner tips with
    • 2 or 3 open leaves 2½-4” long (not more, not fewer, the researchers say).
    •  “Pegs” or nubs of developing roots, or roots up to ½” in length.
    • Large diameter crowns – pencil thickness if possible. Large = more flowers next year.
    • First or second position on the runner, not more distant from the mother.
    • Clip off any secondary runners coming from the daughter plants.
    • Sort the tips by size, planting that same day in 50 cell plug flats with like-sized tips, for best results.
    • Put the flats in a coldframe, water well, cover with thin white poly sheet (bin liner type), lightly perforated. Add shadecloth. Keep moist by watering daily as needed.
  • July 15-21: Continue daily watering. Remove shadecloth. Count live plants, harvest and pot more as needed.
  • July 22-28: Continue daily watering. Remove plastic, replace with rowcover. Harvest and pot more as needed.
  • July 29-Aug 4: Continue daily watering. Remove rowcover. Harvest and pot more if needed.
  • Aug 5-11: Continue daily watering. Harvest and pot more if needed. Remove shadecloth, plastic, rowcover from later harvested plants when appropriate.
  • Aug 12-Sept 1: Plant two staggered rows with plants 12” apart in all directions. Choose the biggest healthiest plants – it makes a lot of difference to the yield!

I reckon in our climate mid-September is about the last date for planting out new strawberries. If we miss that date, we should probably wait till February and lose a year’s production. Sad thought.

I want to explain how the 1/2″ of runner acts as a peg to hole the runner tip in the soil. No-one explained this to me when I first tried it, and at first it made no sense. Push the anchor at about a 45 degree angle into the soil in the plug flat. When the anchor is all in the soil,  press down with your thumb on the side of the crown of the plant opposite the anchor and turn the plant to stand it up. When you get it right it’s a wonderful thing – quick and elegant.

And I should say that propagating from unpatented varieties is fine, but propagating from patented varieties, even for your own use, is annoying illegal.

home-hhf-2013Meanwhile, I’m preparing my presentations for the Heritage Harvest Festival. If you are anywhere in central Virginia, consider going to this lovely event at Monticello, near Charlottesville. The weather forecast is very pleasant, the setting is delightful. Saturday 9/7 is the day. Click the link to read about the schedules, the vendors and the fun events. On Friday at 9am I’m doing a presentation on Asian Greens (there’s still some $10 tickets available for that one) and on Saturday at 10.30 I’m doing Succession Planting. That one is sold out. I’ll also be doing book signings at the Monticello Store after each of my workshops.

After the weekend, I’ll post my slideshows on SlideShare.net, and probably embed one in my next blog post, for those who miss the live show, and those that want to watch it again.