Thursday, 29 January 2009

Keeping Our Plants Alive During the Heat


I've been thinking a lot lately about how we can keep our gardens going and keep producing food during the hot weather we've been having.


Maybe the main culprit is not the heat but the dryness of the air? Certainly here, the humidity is usually close to zero during the summer heat and the air seems to suck the moisture out of everything.

The beans form nicely on the climbing bean plants, but they almost dry on the bush before they are fully developed. The plants look fine and are mulched and watered, but the air is so dry it dries out the fruit as it hangs on the plant.

So, I've been trying to think of ways to reduce the evaporation from my plants. Things like the old sheet canopy I put over the carrots to get them to germinate or possibly some sort of shade tunnel that could also be used to ward off the first few frosts? Or get the food forest thing happening in the orchard . . .

Then last night I was visiting Molly's blog and she had a post about some online resources. Adding to my heat-induced sleep deficit (yawn!), I decided to pay the site a visit. I found an article by William Albrecht which claimed that the absence of water was not what damaged plants during drought, but the fertility and depth of the soil. That is, plant hunger, rather than plant thirst!

Dr Albrecht's basic argument is that if soil is prepared and made fertile to greater depths than used in conventional agriculture that the plants will use the available water in the soil more completely and more efficiently. He cites experiments to support his theory.

Interestingly, the vegie bed that is best surviving the heat at my place is the one in which I grew the oats last winter. The oats left the soil in a very fine tilth, although not that deep. Because I thought the oats might have taken out a lot of nutrients, I gave that bed twice the amount of manure that I normally do. I also gave it a good dig over to distribute the manure. This bed is planted up fairly densely with sweet corn, tomatoes and rockmelons and is coping much better than the maize in the next bed.

The other bed still coping very well is the asparagus bed, which I heavily manure twice a year and give the odd dose of seaweed extract and fish emulsion. The asparagus are barely fluttering a fern with the heat.

Well, it could be canopy cover - both of these beds have good leafy coverage. But so do some of the other beds. It could be the plants, but the same plants in other beds are not coping nearly as well with the heat. It could be the mulch, but most of the other beds are mulched as well, if not better. And, if anything, the maize bed gets more water than the sweet corn bed and certainly more than the asparagus bed.

So, maybe William Albrecht's studies have something to show us - prepare the soil well and deep to maximise fertility and the plants will survive. It's certainly made me think about doing much more preparation in the garden this winter to try to build the humus and soil fertility.

Which brings me to another point. In naturopathy, we talk about a person's vitality. The theory is that the more vital the person (physically, mentally, emotionally, spiritually), that the more likely they are to be resistant to disease and the more resilient they are likely to be.

Surely the same must apply to our gardens. We can't stop the heat, but maybe we can build our gardens to be more resilient to it.

Forecasts about climate change are predicting temperature rises of 0.4C to 2C by 2030, with more hot days over 35C.

This means we need to build our gardens to be able to cope with more summers like this one. I'm going to be putting some serious thought into this and I would love to hear any ideas you may have about how we can help our plants survive. I'd also love to hear if you have some areas of your garden surviving the heat better than others and what the differentiating factors might be.

love and light
naturewitch

10 comments:

molly said...

Hey NW, glad you found something useful on the site, it certainly has a wealth of information available.

I would recommend worm wicking beds, they are deep, constantly fertilised by the worms and wick the water up, hence very little evaporation. Add shade cloth canopies and you will wonder why you never thought about it before (we certainly did lol). Its the only way to garden in aussie I believe.

You can find the plans and details on the worm wicking beds under my "how to" section on the right o the blog:)

naturewitch said...

Hi Molly

Good thought, but that would probably mean dismantling my current raised garden beds. Being made of Besser block, they actually work well during the cooler months. The issue is the hot dry summers.

So maybe the food forest is the way to go for us. We have the trees (although some of them are not that big yet), so I was thinking if I mulched underneath and grew things in layers . . .

My problem is that I get very little assistance with the garden, so it is mostly my labour. And with work and study, it would be hard to renovate to the level the wicking beds would require.

Hence, my thought of digging in more humus to the existing beds and providing them some shade.

Will give this some more thought. xx

molly said...

The forest should work with a ton of mulch or you could take the soil out of the blocks, build the wicking bed into that, would be easy enough if they were built at least a couple of feet high.. I'd try the forest option first, see how it works for you and leave the wicking bed as a last resort.

Cheryl said...

Hi Naturewitch....too hot for me!!
We had a drought situation three years ago.....hosepipe ban and temperatures way above normal right through till November of that year. When I was in India many years ago they added a lot of shredded paper to their garden compost. Most of them grew their own vegetables otherwise they would starve. They had a fantastic success rate. I now add a lot of shredded paper to my compost bins and mix well. The beds that I have used it on have shown much better growth during long dry spells......and the worms seems to love it.

I agree with the last paragraph totally.....I have learned to take care of myself over the years by listening to my inner self....I also listen to my garden....I know that sounds strange but I walk the area every day making a mental note of changes.....I have learned to heal my garden and in return she heals me......

TheCrone said...

Hey gorgeous,

Another great post by you!

A couple of weeks ago we had the run of 15 days over 35 (with one day hitting over 40) and every single tomato plant fried to a crisp. All my lettuces disappeared :( These were in my strawbale beds, 50cm's of mushroom compost and mulched. The only plants to survive in the strawbale beds were kale.

What survived elsewhere in the garden? Everything. I think the reason for this is because they are in a fledgeling food forest. None of my canopy trees are taller than two meters yet but they have provided enough cover to stop the other plants frying.

I am going to get some more shade cloth today to pitch a tent over my freshly planted tomatoes.

Wish me luck!

naturewitch said...

Hi Molly

Yes, I was contemplating the wicking beds again this morning on the bus. I intend to dig them over really well this winter and manure them more than usual to build up the humus and fertility.

So, I was thinking that while I was digging over, I could put in the ag pipe and the feeder pipe. The beds are mostly 3 Besser blocks or 2' high, so I think they'll be deep enough.

And my original thought about shades would work as a kind of shade house. If I used the hoops, then the shade cloth could be replaced with some sort of plastic film in winter and I'd have cloches.

Lots of work, but I think it will be worth it. Thanks for all the info - I've also passed it on to someone at work who is about to build some vege beds. xx

naturewitch said...

Hi Cheryl

We use shredded paper too. I put it in the compost, but also use it to layer up the potato beds.

When I build a potato bed I start from the ground, place potatoes at intervals and then layer up like a lasagne, with layers of straw or hay, manure and blood and bone, paper, then manure and blood and bone again, then straw or hay, etc, etc.

It's an easy way to get the potatoes growing and they are very easy to pick afterwards - just lift the layer of mulch.

We do need to listen to our gardens; they are a source of such abundance for us and hopefully we are for them too.

I realised this morning that when we are ill or stressed we often take vitamins or herbs to help us through.

Using that logic, our gardens will also need extra nutrients to get them through stressful periods. So, the findings of William Albrecht's studies make perfect sense.

I wonder if extra nutrients would also help plants deal better with the cold and make them less prone to frostbite? Seems like we might have some interesting experiments coming up! Have you noticed anything that makes plants survive the cold better? Interested to hear. xx

naturewitch said...

Hey Crone

So sad to hear about your tomato and lettuce losses. Would make my heart break. {{hugs}}
Hope your new tomatoes survive under the shade cloth.

Unfortunately, I think these conversations are going to become more common in the years ahead.

As for the food forest - great news! I'm convinced they are one of the ways forward, but they take a few years to get going. We just have to work at these things bit by bit.

Good luck with the rest of the summer. xx

River said...

It all sounds perectly feasible to me. Nutritious soil is something I firmly believe in. Compost and manure, plus a little fish emulsion now and again, blood and bone, all that sort of stuff. Hubby's a fan of wettasoil and cheap fertilisers like thrive, and that stressguard stuff tht you spray on foliage. since he's been looking after the garden more plants have died than I've had hot dinners. Still, there's no arguing with him when he's convinced he's right.

naturewitch said...

Hi River
Good luck with that one! xx