​The Polytunnel in April

​The Polytunnel in April

growing guide for the polytunnel in April

So, how is everyone feeling with the improvement in the weather? I for one am feeling pretty good about it. I don't know what the temperatures were like where you are, but it was wonderfully warm in my garden at the weekend - with growth everywhere suddenly taking off. Of course this also means weeds have got moving too, as have enormous populations of slugs which I will get to later (as I need to take some drastic action). 

Jalapeno chillies on a heat bench in the polytunnel

In this blog post we'll take a quick look at some of my polytunnel crops; there may be some information that will be useful to you. Above you can see Jalepeno chillies coming on nicely, with good stocky growth: meaning our heat/light balance is about right. I have peppers on the same heat bench as the tomatoes at a low temperature of 15˚C, which keeps them protected while not letting them grow too fast. It can be tempting to just water the whole bench in one go, but I need to be careful with peppers: they are much smaller, slower growing plants than tomatoes so need significantly less water. 

growing tomato plants in the polytunnel

You can see the tomato plants above, photo taken yesterday. I had potted them on 10 days ago from 7 to 12 cm pots and given them plenty of room to grow by spacing them out on the bench. A heat bench set at 15˚C will hardly ever be on, but gives just enough heat if temperatures drop to maintain steady growth. The above plants are about perfect (though I say myself). 

Again I need my wits about me as I have a mix of bush and cordon (tall) varieties. Unlike Cordon varieties, bush tomatoes should not have their side shoots removed so I need to careful not to break them off out of habit. 

Maskotka tomato plants, tasty cherry tomatoes

You can see the bush tomato 'Maskotka' here, which gives very early crops of super tasting large cherry tomatoes. Despite still growing in its nursery pot, you can see the little plant is already starting to flower: very exciting so early in the season!

The weather is promised relatively warm and sunny for the next week with the tunnel really heating up, so I might risk planting my Maskotka in the beds towards the end of next week. All tomatoes will grow very fast in warm weather, so they will either need to be potted on or planted in the beds to prevent them getting pot bound. 

Sweetcorn in 9cm pots

Sweetcorn
This photo was taken only 3 or 4 days before the tomato ones above, which shows just how quickly the tomatoes are growing (you can see noticeably smaller plants in the background). In the foreground we have sweetcorn in 9 cm pots, having been potted on 2 weeks ago. 

Sweetcorn is another plant that you can nearly see growing in warm weather. It doesn't like root disturbance either, so I think the weekend will need to see these planted in the tunnel beds also. As I think I said before, sweetcorn can be grown well outside but needs warmth. This is an early polytunnel crop; for outside wait until May to sow. 

hardneck and softneck garlic growing together in the polytunnel

Hardneck and Softneck Garlic
The garlic is also going great guns and is well on track for harvesting in mid to late May (outdoor plants will be late June). I have a mix of varieties, with hardneck 'Primor' in the foreground and softneck 'Therador' and 'Germidour' behind. Hardneck varieties are taller and produce curly edible scapes (these should start any day now), while softnecks don't. 

You can also see by the height of the leaves that the bulbs are already beginning to develop, so I need to make sure they have plenty of water now to allow them to swell. 

interplanting carrots with lettuce

Interplanting
Above we can see carrots - which are a little slow this year but are just starting to take off. I have used the space between the rows for lettuce, which will have given many leafy harvests before the carrots need the space. Interplanting makes sense anywhere in the garden, but especially in the tunnel when space tends to be at a premium.

early calabrese and spring cabbage growing side by side in the polytunnel

You can see the same principal above, where I have a bed of early calabrese and spring cabbage growing side by side with lollo rosso and lollo bionda lettuce. I get such a kick out of seeing all this vigorous growth: it really is a whole other world in the tunnel at this time of year, with a totally different climate to the outdoor garden. 

I would also note, before you read the next bit, that there is hardly a slug or snail in sight - a marked contrast to what's going on outside! 

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slugs munching on leaves

Slugggggs! 
I cannot believe the amount of slugs and snails I have around the garden this year: if I go out in the early morning the place is literally covered in them. Not so good of course for my seedlings, which will be completely demolished if I don't take some drastic action. I have had half of my broad beans eaten down to stumps, pea rows have been 'thinned' and they are even having a go at the onions. The gloves will have to come off. 

First off, I won't be planting anything else outside until I have the upper hand - there is literally no point. This is not really a problem, as I can pot on seedling plants from trays into small pots to buy me some time. I will also be making sure I have a few spares, as I am sure we will have some casualties no matter how successful I am. The other advantage of growing on larger plants is that they won't be wiped out in a single slug attack (like smaller seedlings), so should stand a chance once they are planted out. 

Slug Habitats
Opinions will differ on this, but I do think it's OK to use wildlife-friendly slug pellets from time to time; though I try to keep their use to a minimum. If you have a major slug problem, pellets will play a part in turning things around - but unless you tackle the underlying problem, you are probably wasting your time (and money). 

a suitable habitat for slugs

The bottom line is that your slimy diners need somewhere to call home - and if you are providing this accommodation, you (or me in this case) are part of the problem. As detailed in an earlier mail, I had let the garden get a bit out of hand last year with some long grass and weeds being allowed to grow around the perimeter, which is normally cut with the mower. 

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I had tidied up this area last Autumn with the mower on a high setting, but there was still a thatch of old grass at soil level which didn't get cut. Yesterday evening was spent on hands and knees pulling back the old grass to reveal a quite astonishing amount of slugs (3 of which are pictured above). The normal suspects for slug habitats are piles of rocks, wood or other material, which provide a cool, damp and dark hiding place; so I was surprised to find so many in the grass - a lesson learned. 

a veritable colony of slugs

The amount I collected last night is too gruesome to show here - plus my phone ran out of batteries (I was using the torch), so I couldn't take a picture. It was nearly a third of a bucket. I picked this little lot above in about 10 minutes before I left for work this morning. 

Homing slugs
While I had very little goodwill towards this lot, I couldn't bring myself to kill them; so decided to fire them into a ditch a good step away from the garden. It turns out that slugs and snails have a homing instinct and will come back to your garden if you move them - although it appears this can be overcome by distance. 

Research by the university of Exeter (odd research always seems to be done by the university of Exeter) has shown that slugs and snails won't return if deposited 20 metres or more away: so if you are only throwing them over your neighbour's fence, they will be back. You need to work on your throwing arm. 

ferric phosphate pellets

I am using organic-approved ferric phosphate pellets around any seedlings I have in the garden, as I have to protect what I have. I also have a some beer traps out (I find the 'Slug-X' is the best one), but didn't find many drinkers this morning. I will keep you posted on the efficacy on the control methods; I understand from questions on social media that they are a problem for many of you this year!