At this time of year, it is important to get the seeds of the new winter season off to a good start while the soil is still warm. But there is a bit of a problem with this. The majority of the seedlings that will grow well over the winter months are brassicas. They generally do better than then their summer compatriots as they are un-harried by the cabbage white butterfly as the cool conditions don’t suit their tender bits. It is so refreshing to harvest a broccoli in the winter without spending ages picking out the extra protein and then eating with caution – not that you tell the family… “Eat ya greens, its good for you!”
However, in these early days the butterflies are still flitting about as it is still warm enough for them and just one egg laid on a vulnerable seedling can grow into a caterpillar that can demolish the seedling in just a few days. But the butterflies don’t just stop with one egg per plant, your poor brassica seedling finds itself food for many, long before it becomes food for you.
I have struggled with this problem for years. I have used cake nets, kept seedlings indoors until the last moment. I did regular check and squish inspections. I’ve liberally sprinkled derris dust and I’ve been at my wits end.
The other problem at this time of year it is still too hot for tender seedlings in conditions where there is no rain and so the potential to fry seedlings in a moment’s inattention after weeks of tender care is huge. The only really upside to starting from seed at this time of year is things grow so much quicker than in spring so there is less of the ‘will they germinate’ angst and they appear long before you consider giving the soil a bit of a poke to see what is going on. And of course the obvious… you get things to eat mid-winter!
Now in my new garden I have the luxury of a nursery bed, one to grow these autumn seedlings beyond the confines of pots, taking advantage of the moisture deep in the soil and reducing the risk of pots drying out. I’ve always wanted one and am excited to have it. The soil is low nutrient as the seedlings don’t really need a heavy rich soil. What that means is I haven’t added compost and well-rotted manure or anything, but I may tickle it with a little bit of something, so it isn’t completely devoid of nutrients – other that what is in the soil. And it is fully irrigated, so the seedlings can have their thirst quenched easily.
So, I was all set to go with the seeds, but the butterfly conundrum held me back… and I gave the problem a lot of thought. I did buy a tunnel house to protect the seedlings, but it was too small for the bed, so space was wasted and it created gaps around the irrigation tubes, and I caught a butterfly in there and the few seedlings I was trying to protect ended up with holes in their leaves.
Then I came up with a crazy plan, that actually worked! I’m so pleased and now I can sow my seeds knowing not only are the seedlings safe from ravenous green creatures and are protected from the heat of the midday sun.
This is what I did:
Come again soon – the seeds are in and the will come alive once again.
Sarah the Gardener : o)
NB: clicking on the images will give step by step instructions.
That cabbage white butterfly looks ‘identical’ to that which used to be so common here, thousands of miles away on the West Coast of North America! Seriously, it looks the same! They are not so common now that all the orchards are gone. They liked all the mustard that grew as a cover crop under the orchards.
They are still abundant here in the Midwest!
We can share in the frustration at this one in our gardens… not all butterflies are nice and pretty! : o)
Since reading about this, my colleague down in Southern California and I have been talking about the swarming ‘painted lady’ butterflies. They or the similar monarch butterflies do this every so often. He notices them in huge herds in particular areas, but there are many others in between the herds. There were not so bad in Mid City Los Angeles or Beverly Hills, but were swarming just above the pavement on the freeways between Downtown Los Angeles and the San Fernando Valley. They are apparently even thicker around Palm Springs.
I saw a video of that recently, the Painted Ladies were all flying along a beach! They looked amazing! Although I wouldn’t like to see a swam of Cabbage Whites – that would be the stuff of nightmares for keen gardeners! : o)
Yup that’s the one. Mustard is a brassica so they would have no trouble switching over to your cabbages! They are very common here – possibly too common for a migrant that has only been here just under a hundred years! : o)
I love your nursery bed, what a good idea! The cabbage white butterfly is so cunning – I found it impossible to keep them off my rocket which I had growing in pots and I had placed some wire trays over them but the caterpillars won in the end. I’m waiting for cooler weather before sowing any more.
They are such a pain in the garden! It doesn’t help that I have a prolific weed in the brassica family all around my garden and I didn’t pull it out when I should have as the bees were loving the flowers so now I have seeds from it everywhere. It will be even more of a nightmare next year, but hopefully the cage will at least keep my brassica safe for now. : o)
what a fabulous space!
Thank you so much. : o)