Powdery Mildew

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Following the posts about courgettes and cucumbers, I need to follow up the depressing facts about powdery mildew with a possible preventative or cure.

Grow For Flavour

I was given ‘Grow for Flavour’ by James Wong as a birthday gift a year ago. In his section about growing cucurbits, James Wong wrote about an interesting concoction he named ‘Supersquash Tonic Spray’ which I was taken by as some of my cucurbits were starting to show signs of that horrid virus, especially my pumpkins. My cucumbers and butternut squashes fortunately escaped unscathed but I was very afraid for the lives of my courgettes (which the disease did eventually slow down to a halt in early autumn) and my pumpkins (that fortunately managed to hang in there until they were ready for harvesting, then the powdery mildew reached the stems and rotted them). James Wong’s spray is for preventing the disease from taking hold of the plants but it was a little late for that last year by the time I got the book. We used it as a way of trying to hold back the disease. We don’t know if it was the tonic or just some strong cucurbits fighting for their lives, but the powdery mildew was kept at bay – it didn’t vanish but it didn’t go out of control and kill of the plants straight away.

This year, we started using the tonic spray on the plants that could possibly suffer from a powdery mildew attack as soon as they were in the ground. The weather has been so odd this year that we really do fear for any plant disease coming along so it is best to be prepared.

If you read the ‘Life’ section that comes with the ‘Telegraph’ paper (my grandma gives them to us for the chicken houses every week), then a slightly recent article written by Bunny Guinness mentioned that she now uses a 50/50 milk and water solution to spray her cucurbits with to cope with powdery mildew too.

Here is the concoction we make to help keep our cucurbits strong and healthy to fight powdery mildew when it attacks, from James Wong’s ‘Grow for Flavour’ instructions (all credit goes to the author):

Supersquash Tonic Spray

Add a splash of seaweed extract to 1 litre (1 3/4 pint) spray can of water along with a 1/4 of 300mg soluble aspirin tablet. Add a splash of full-fat milk for added nutrient content. Spritz the tonic spray over the plants’ leaves whenever you can but at least once a month over the summer. Saturate the leaves as much as you can.

The science:

  • Trials at the US Dept of Agriculture have shown that a foiler spray rich in potassium improved the quality of melons (squash’s close relative) by improving the firmness and sugar content and increasing vitamin C and beta-carotene levels.
  • Trials have demonstrated that chemicals closely related to aspirin can act as a tonic to help boost squash plant defences against drought and cold. Experimental evidence suggests that aspirin spray can improve their resistance to disease such as mildew and mosaic virus.
  • Wong emphasises using full-fat milk, not skimmed or soy. The fatty acids in milk have been shown in some trials to inhibit the growth of mildew.

Wong does point out that neither aspirin or milk are approved formally as registered pesticides or for the treatment or prevention of plant diseases. It is entirely legal though to apply them to boost plant growth and crop flavour.

As I mentioned before, all credit for the recipe and facts goes to James Wong’s published work. Give it a go!

Storing your pickings

So there are plenty of fruits and vegetables in the world and only so many hours to talk about how to store them. Perhaps we should start with what is around right now and work from there?

Salad leavesLettuce, rocket, watercress and other cresses, like land cress or crinkle cress, (watercress wilts quickest) and spinach (wilts second quickest) are best eaten straight away once they have been picked and washed. To store it, I put mine in containers in the fridge mostly because I know I will be using it over the next few days. Other people keep theirs in plastic bags or between kitchen roll. If you have left the salad out for too long and it has wilted, leave it in a bowl of cold water to rejuvenate it before refrigerating it immediately. You can freeze green leaves, like spinach or lettuce but they will be incredibly soggy and are only useful for cooking. You might as well stick to fresh leaves rather than freezing them.

Carrots – If you are using them over a couple of days then they can be again kept in the fridge in a plastic bag or a container. Otherwise, the traditional way of storing them is in a cool, dark place in a box filled with dry sand. This can also be done to swedes, celeriac, sweet chestnuts, parsnips, celery and beetroot (celery will keep in the fridge for ages. Swedes and celeriac can be left in the ground for months at a time).

Peas – Best eaten as soon as they have been podded if consumed raw. If they are slightly too old to be delicate enough to eat raw, pop them into a pan of boiling water for 2 minutes, drain and serve. To freeze them, once you have boiled them, place them in freezing ice-cold water for a few minutes until cool. Place them in plastic bags ideal for the freezer, make sure no air has been caught inside. Freeze them and use over the next few months. This is the same technique for runner beans, broad beans or sweetcorn (by the way, sweetcorn loses its taste rapidly after being picked. It needs to be cooked and eaten or frozen asap).

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Pod and eat peas and broad beans boiled straight away or freeze after boiling and cooling briefly

Onions – Once pulled out of the ground, lay them out on newspaper to dry out, turning them over so that both sides are dealt with. Then, suspend them from the ceiling in a cool room or inside hessian/netted sacks. We use our utility room as it is very cool and is not too light.

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Dry onions out on newspaper before hanging up

Garlic – harvest the bulbs whole from the ground and place in a cool, dark place. We keep ours on a low-down shelf in out kitchen. When using, take one segment from the  entire garlic bulb at a time, peel and use. From my experience, homegrown garlic tends not to keep as long as shop bought garlic so only pull them up from the ground a little at a time, don’t be tempted to harvest them all at once.

Potatoes – I worked out last year that potatoes can be left in the ground for a long time and you do not need to rush to dig them up unless you have a wire worm or slug problem. Even if they have blight, they will keep better in the ground rather than out of it. However, to store them once they have been harvested, copy the same technique used for drying onions, laying them out on newspaper and turning them over. Then put them inside hessian sacks in a dark place, like a cupboard under the stairs to prevent them from turning green and becoming unusable.

Berries – If you can’t eat them all fresh at once because you have a glut or want to spread them out for later in the year, freeze them in plastic bags or containers once they have been washed and slightly dried. To use them, defrost well and drain the excess liquids that will taste a little to fridgey. Some berries like raspberries, blueberries or grapes should taste fine uncooked once they have been frozen. Other berries, like strawberries, have such a high water content that they will taste strange once defrosted raw. I prefer to use my frozen fruit for jam or inside cooked puddings, like muffins, cakes, stewed fruit dishes, crumbles or pies. I save the fresh fruit for eating uncooked.

Summer squashes: Courgettes – You might have been starting to pick some already. These are best sliced from the plant, washed and cooked straight away but can be stored in the fridge for a couple of days, depending on the variety and the ripeness of the vegetable. Best stored in an air-tight container or a plastic bag. Boil, fry, grill or roast them. Courgettes cannot be frozen because of their high water content, much like strawberries. Winter squashes (e.g. Butternut squashes and pumpkins can be frozen once they have been roasted – Slice, into small pieces, lay out on a baking tray and drizzle generously in olive oil. Roast in a preheated oven of 180C for about 40 minutes or until they are browned. Allow to cool. Place in plastic bags and freeze straight away). Courgettes and cucumbers will only become sloppy mush when frozen so do store them only in the fridge or eat straight away.

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Courgettes are best eaten straight away or stored in a fridge – do not freeze them or cucumbers (below)

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Cabbages: Can be stored whole in the fridge for a few days. If the outer leaves start to brown, wilt too much or go mushy, peel them off and discard them and use the rest if unaffected. If cooked, cabbages can last in a container for about three days. This is the same for cauliflower and broccoli (broccoli seems to brown slightly quicker out of the two when stored in the fridge).

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Romanesco cauliflower prepared for boiling

Spring Onions – Can be kept in the fridge for a couple of days. If the outside skin starts to dry up or the stem wilts too much, cut and peel the outside coating off and use what is underneath if it is unaffected.

Radishes – Likewise, they can be stored whole in the fridge or cut up and kept raw in a container for about two or three days before they will start to brown and become un-appetising.

Kale – Store in an air-tight container, raw, for up to a week maximum inside the fridge. Once cooked, store in a container for two or three days in the fridge.

Oriental greens – Think Pak Choi, Tatsoi, Komatsuna, Chinese Cabbage, Mibuna, Mitzuna, Mizpoona… Once cooked, they can be stored for about two days. Raw, they might be able to last a little longer in the fridge before they wilt or turn to liquid. Treat them more like spinach, liable to becoming soggy after some time being picked.

Tomatoes – It might be slightly early to write about tomatoes but it is getting close enough. I did not know until last year that tomatoes keep their looks and taste longer if stored outside the fridge. Gardner James Wong (‘Grow for Flavour’) suggests keeping them in a fruit bowl. We tried this last year and it does work well. It also allows some of the slightly under-developed ones to ripen. If freezing the tomatoes, dunk them briefly into a pan of boiling water to shed their skins before placing them into cold water, likewise for the beans and peas. Store in plastic bags in the freezer and use in dishes where you would use cooked/tinned tomatoes or make tomato chutney.

 

That is it for now. More coming soon…