When does drought begin?

It’s been several years since I have gone through a drought summer but I might be at the beginnings of one this year and extended forecasts don’t look good.

Based on personal experience, mostly based on a lawn surviving during the first year or two after being put in, my personal rule of thumb is that a drought starts on the 3rd week of high heat since the last significant rainfall.  For example, if we got a soaking rain on June 1, followed by three weeks of no rain and high heat, the drought itself would begin on June 21 or 22 or so.  That seems to be how long it takes for grasses to dry out and turn yellow/brown and become fire prone.

Unfortunately, although we did get a heavy rain about 10 days ago, it had been almost 2 weeks since the previous rain and temperatures in the 90’s.  Since that last rain, the temperatures have been in the 90s and if the current conditions continue, my lawn will be pretty yellow and dry pretty soon though I am more concerned about other plants

As much as I have preached the merits of gardening in wood chips, today I planted my last 2 cucumbers and sadly the chip part of the bed (several inches) was completely dry as in dusty dry.  I am accustomed to wood chips holding moisture but that is not the case this year.  I have not irrigated my garden in over 10 years but apparently I will have to this year.  Ah well,  It was a good run while it lasted.

My heavily decomposed chips sit atop heavy clay subsoil so some deeper rooted crops can still get moisture from there.  It looks like I will have to drag out 5 gallon buckets to irrigate the plants.

But back to the original question, how do you define the beginning of a drought?  I know this is a highly regionalized question but I am curious to know the different thoughts.

Eric

Drought is when your drought-resistant plants start asking for help.

My buffalo grass is dying. There is not much I can do to help as I have 40 acres that buffalo grass is trying its best to take over.

So far that is the only plant having problems maybe the other plants have deeper roots.

There are a lot of definitions for drought. From Mr. Google, A drought is a period of time when an area or region experiences below-normal precipitation.

I know the various technical definitions of drought, including the generic “a period of below average rainfall”, but I was just curious what constitutes drought to different people.  Personally I didn’t think anything could make buffalo grass turn dry but I guess I am wrong.  By me, 3 weeks of heat without significant rain seems to suck all the moisture out of the clay subsoil.  And I know that what I consider drought is a wet year for some.  That’s why I was wondering what different people considered drought to be, but I like the idea of drought beginning when drought resistant plants get heat stressed.

Eric

We often don't get ground wetting rain for two months with temperatures in the 30s, up to 40C. We might get a sprinkle here and there, but then the sun comes out and it all evaporates right away. Sometimes we don't get a single drop for more than two months.

Because drought is so subjective I don't bother using the word much. Even using your drought tolerant plants as a benchmark doesn't mean much, except to you. Drought tolerant plants grown in irrigated gardens for generations wouldn't survive if they were suddenly transported to a dryland garden. Different soil will make a difference, how much wind you get, etc.

This year has been very cool and rainy. We haven't even hit 30° yet. It's been sunny and mid 20s the last few days. The sun is hot, but the air temperature is still cool. A lot of my plants are stressed and wilty when the sun is out and it's only been a few days since it last rained. I think they've gotten water fat. They didn't complain this much during the heat dome last year!

Jan said, " Drought tolerant plants grown in irrigated gardens for generations wouldn't survive if they were suddenly transported to a dryland garden.

Maybe I used the wrong wording.

My never watered plants are all doing okay except the buffalo grass is asking for help. The buffalo grass never gets watered that is why I love it.

My dirt is rocky caliche so that doesn't help either.  Many folks don't know what caliche is.  It is not soil it is made by mother nature from limestone.

I would love to hear about others who are experiencing drought and how do you know you are in a drought.

Too many days of too hot temp and no rain in sight and when we get some rain it is 1/100th of an inch.

The weatherman keeps predicting Hot, hot, hot... with no rain.

This year we didn't get the beautiful wildflowers that the spring rains bring because we didn't get any rain.

One benefit this year is no weeds to pull.

I can't say for sure that I am in a drought though I feel I am.

The official definition is when the rainfall is significantly less than normal.

Our "normal" is zero for 5 to 6 months every summer.  So we don't officially have "drought" here.

Personally, I go by soil moisture and our water table.  If our well can't handle, regular chores, having a bath and doing the laundry on the same day, then we're in drought mode.  That can happen almost any time of year, even in the rainy season, depending on the kind of rainfall we're getting.  This year, I expect to get there in about a week from now.  

I like measuring drought by soil moisture as do many farmers.

The official definition pertaining to low rainfall derives from meteorologists.

Limnologists (Scientist who studies lakes and streams) often measure drought by river, lake and stream levels.

Seems like just about any discipline can measure drought by just about whatever means seem appropriate.

Eric

I agree that it can be tremendously location dependent. My sister's in Ontario. They may get 3 weeks of no rain then one humungous thunderstorm that meets their "monthly average rainfall", but the plants don't agree with the statisticians!

To me, what matters the most is what the plants say. As I improve my soil, and bury punky wood in key places, I still need to water, but far less than what my neighbors and friends do. Maybe if I'd started from scratch with a proper permaculture plan that included water management, I'd be further ahead, but I bought an existing property with a fair bit of infrastructure already here, and I'd never heard the word "permaculture" at the time. I'm pleased that I've improved things as much as I have, but I'm also scared for the future with all the crazy weather we've had in the last 2 years. I feel like I'm not producing enough food, I'm not able to store food the way it needs to be stored,  we're dependent on far too much off-property resources, and I'm not getting any younger. I try to focus on what I *can* do, and what I feel I'm doing "right" - or at least as right as possible under the circumstances.

That said, another indicator I use personally is when the deer start breaking into my garden - that tells me that the "easy" food is gone! Sounds like a drought to me!

Ok, I think that for practical, gardening purposes I have to say that I am experiencing drought conditions as I need to do something that I haven’t done in about 10 years—irrigate!

This year I only have one bed planted due to some spring chaos.  I am (attempting) growing yellow neck squash, cucumbers and tomatoes.  I got the cucumbers in just last week because I needed to make a trellis first.  I thought I had enough moisture down deep in my woodchips but when I checked yesterday, one cucumber plant was laying flat and wilted.  It has a little bit of brown on the edges of its leaves.  I therefore went out and dumped 2.5 gallons (1 cat litter container) on those two cucumber plants and by this morning they had both perked up with one even grasping the trellis and the wilted one at least trying to stand.

My tomatoes did not look so great either.  They were definitely dry and clearly not growing as fast as they should.  This morning I went out and bought a hose so I could actually water thoroughly in the mornings and at the store it looked like pretty much everyone was buying hoses, sprinklers, water wands, etc.

This will definitely be a challenging year for my mushroom beds (no mushrooms growing this year) as my mushroom compost has never been so dry.  In the past it has acted much like a sponge—absorbing water and holding it for slow release.  This year it acts like a dry sponge—it is so dry that it does not want to accept water that falls on it.

I probably will end up watering on a daily basis now, but this is kinda sad.  In years past my mushroom compost was highly drought resistant but the recent heat and lack of rain has really dried things out.  I even have an irrigation system installed out by my garden but it is buried under one of my mushroom beds!  To use it I would have to dig it out!  I really thought I was past using this but this summer may be the ultimate test.

Last point:  this is the first time growing cucumbers (my wife requested them).  Does anyone have any tips on growing them?  I know they need a trellis and one is in place.  I am certainly open to pointers.

Eric

I think the key is the heat as much as the rainfall. Here we generally get rain every few days, but usually in Spring we get a dryish spell that can last from the end of March to the middle of June. Sometimes it's a lot shorter, sometimes longer. I think we were approaching drought in 2009 (or 2010?) when we had 16 weeks without rain. The burn (stream) that runs through our property and is fed by deep springs was just about dry. Although the springs were still running, they soaked away rather than running off. The surface springs, which come and go more, all dried up - one way of telling whether your spring is a good one! Although our soil is very shallow over rock, because the dry spell was still cool (max 18 deg C or so) only the grasses on the shallowest soils went yellow. There was no restriction on the council water mains, so not a real drought. If we had the sort of summer temperatures that are normal in much of North America it would have been a very different story....

Eric Hanson wrote:

I probably will end up watering on a daily basis now, but this is kinda sad.  In years past my mushroom compost was highly drought resistant but the recent heat and lack of rain has really dried things out.

The downside of wood chips when things dry out completely, is that the water doesn't get down through them to the soil as easily. If you're up to an experiment, take one bed and try putting the sprinkler on very low *all night*. The water has to be sprinkling lightly enough that it doesn't just run off/run through. Compare that to a daily water regime on a different bed. Granted, we don't get as hot as you do, so you may find you have to do an overnight sprinkle every 5 days instead of 7, but with the good soil you've been building, I'd be curious how it goes.

That said, production will be lower with less water. My friend who waters twice a day, gets bigger tomatoes than I do. I don't have the time to water that often because my plants are spread all over - every little patch of sun as light's my limiting factor. But they don't croak either.

Maybe this is a year to set up an outdoor shower uphill/upslope from your garden?? At least the water will get used twice!

I may have sounded the drought alarm a little early.  This morning at around 5:00am we got a good thunderstorm that rolled through.  Since that time (11:30 am as I write) we have had a long, slow, gentle rain—perfect for getting moisture back into the ground.  So technically we did not hit the drought indicator I like to use (3 weeks) but we did have a fairly dry spring, my wood chips had turned to dust, and I watered for the first time in 10 years yesterday.  It remains to be seen how the summer progresses, but for the moment at least, our dry spell is definitely over.

But hot, dry weather is in the forecast and my cucumbers are still in recovery so we will see how things go.

Eric