Friday, 29 July 2016

PSB. Will the spares be needed?

These days I usually grow only 4 Purple Sprouting Broccoli plants each year.

PSB "Red Spear"

In such circumstances, the loss of just one plant would be a reduction of 25% in my cropping-potential, and for this reason, I always raise lots of spare plants so that I can replace any casualties. Very often the maggots of the Cabbage Root Fly manage to destroy one or two plants, and I usually deploy a pack of nematodes to counter-attack them. This year I have had no casualties in the PSB, and I have not applied any nematodes to them. This is largely because I didn't feel the need. Earlier in the year I bought and applied two packs of nematodes to counteract the Root Fly threat to my climbing beans, as I usually do. I saw no signs of Root Fly damage to the beans, and none of them died. I concluded that it was not a bad year for the Root Fly, and decided to omit the later application of nematodes at PSB-planting time. I think I got away with it!

You can see here my 4 plants, which are already settled-in quite nicely and growing OK.

They look a bit pale, and I think that is because they have been fairly stressed by the very hot weather we have had over the last week. I have actually watered them not only in the evening, but also in the middle of the day as well, in what I call Fist Aid Watering, despite which they have drooped a lot, though they recover overnight each time.

Although I really only wanted to have 4 PSB plants, on May 17th I sowed 24, and subsequently potted-up the best 12 - three of each variety! None of the spares have been required this time. I have given away 4 to a friend, and I think the remaining 4 will go the same way shortly. They are still in 5-inch pots and not looking very happy:

However, having good PSB is so important to me that I'm not taking any chances, and I sowed another batch of seeds on 24th June. Brassica seeds are normally pretty cheap, so this is not a great extravagance. This is what the second batch looks like now:

They look good to me. It's almost a shame that I really hope they won't be required.

In a similar vein, I also used up the last few seeds of a packet of "Endeavour" Brokali. Being old seed, it didn't germinate well, and I have ended up with only three little plants. I plan to put them in amongst the Beetroot in the bed which until recently held my Peas.

Since my main brassica crops are protected by nets, the butterflies are searching around for somewhere else to lay their eggs, and they have definitely found the Brokali. Close inspection reveals clutches of eggs on the undersides of many of the leaves:

With only 3 plants to deal with, it won't be a big problem to rub off these eggs, but it just makes me glad that I don't have half an acre of brassica plants to attend to!


  1. 24 extras is certainly a LOT of insurance! Glad that you won't be needing them, as I'm sure your friends are as you pass them off.

  2. To be honest I have never heard of a bean root fly.

    1. I expect that's not its official name. It lays eggs on the roots of bean plants just like the Cabbage Root Fly, and they hatch out into little white/grey grubs that gnaw through the roots of the bean plants, causing them to die.

  3. Hi Mark, love your blog. At what point do you pot on/up the brassicas after they have germinated? I've never quite grasped sowing seed in punnets.

    1. I put the brassicas in 4-inch pots when the plants have at least two true leaves (i.e. discounting the cotyledons). Then I plant them out into the raised beds when they are maybe 6 - 8 inches tall, by which time they probably have at least 2 pairs of bigger leaves. Have a look at my post from 16th April this year...


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