The big picture

We need to talk about seedling stress, writes MICHAEL McCOY. While most will bounce back after a wilt, why not avoid it altogether?

It’s high time I had my winter vegies in the ground. While I’m keen to live in denial of the reality of winter for as long as possible, cool climates like mine (in Woodend, Vic) are unforgiving. Winter vegies really need planting by late summer if they’re going to be big and fat by the time they’re too cold to grow any more.

This puts sowing and planting-out times smack in the middle of the most stressful time of year regarding heat and water. And, if you weren’t already aware of it, it’s time you knew that seedling stress is a thing. It’s not some faddish, new 2020-uncovered stress. It’s been around forever. We just haven’t talked about it enough.

Indeed, I wish someone had told me, early on in my gardening life, that just because seedlings growing in punnets seem capable of remarkable recovery following a severe wilt, it doesn’t mean they should be subjected to it, nor that there won’t be any ill effects. This kind of single-event stress can cause vegetables, and flowers for that matter, to flower and set seed prematurely, and therefore inadequately. Nearly the entire carrot family, including carrots, parsley, fennel and coriander, fall into this category. You may not see the effects immediately, but that one wilting episode, or the shock experienced when dividing up and planting out a pot or punnet of seedlings, may well trigger the eventual response.

Fortunately, a lot of other vegies, including many of the brassicas, are rather more tolerant, and wilting due to dry or excessive heat may only result in a slightly reduced performance. And for a lot of us, not aiming for (or with no hope of ever achieving) perfection, that’s okay.

When it comes to my vegie performance, I accepted a moderately suboptimal outcome a long time ago. If I can achieve, say, 60–70 per cent of perfect harvest performance out of my vegie plants, I’m happy.

Having said that, there are relatively easy ways of providing stress relief, or avoiding it altogether, when it comes to sowing vegies.

For instance, I direct-sow all of the carrot family to avoid transplant shock. With everything else, I’ll make sure that they’re growing in individual pots or plugs before being transplanted, in conditions matching those they’ll be in when they hit the open ground. If I buy a punnet of seedlings, I’ll often pot each seedling up into small pots and keep them somewhere cooler and stress-free until they have a decent root system of their own, then expose them to full sun for several days before transplanting.

At least, that’s what I aim for. It sounds altogether more sensible, organised and tidy on paper than it appears in reality.

Michael blogs at thegardenist.com.au