June 13, 2019

Living in the Shadow of the Rain

Summer in my part of the country usually includes at least one long, hot dry spell. Our recent one started mid-May, with no rain and highs in the 90s F (lower 30s C) for three weeks. None of my summer crops are mature enough yet to have good, deep root systems, so if it hadn't been for our rainwater tanks I would have lost much of my garden. I used 1650 gallons keeping things alive before it finally rained again last weekend. We were blessed with about five inches, which was enough to refill our 1500 rain tank.

To water my upland rice, I figured out that if I put the hose into
the watering can, it was more efficient than the irrigation pipe.

That dry spell was so early this summer that I can't help but wonder if we won't get another one this year. Climate change aside, part of the problem is that we live in the rain shadow of the Appalachian Mountains. Most of our summer weather systems come up off the Gulf of Mexico and travel in a northeasterly direction. Depending how far west they originate, they travel up the west side of the mountain range. As the moisture laden air rises to pass over the mountains it cools, condenses, and rains on the western side of the mountains. By the time it passes over the mountains and gets to our side, it's all rained out! This is called the orthographic or rain shadow effect, and is why there are often deserts on the inland side of mountain ranges.

Rain Shadow Effect. Graphic courtesy of Meg Stewart. 

It's no fun to live with! Fortunately, we get enough rain (roughly 50 inches per year) so that we aren't in a desert. But we get enough hot, dry spells that it warrants paying attention to and planning for. My preparations are three-fold: immediate intervention with collected rainwater and mulch; long-term with soil building.

Soil building because some soil holds moisture better than others. Thriving soil microbiology is key. Mycorrhizal fungi produce a sticky substance called glomalin. Glomalin glues together soil particles, minerals, organic matter, and nutrients to form soil aggregates. Aggregates reduce water and wind erosion, reduce compaction, increase nutrient cycling, and increase water filtration and moisture retention around plant roots. (A detailed PDF can be found here.) The healthier the soil, the better it can retain moisture during dry spells.

Last weekend's rain revived the garden and cooler temperatures have followed. What a relief! The first thing I did was get my sweet potato slips planted. The poor things had been sitting in jars of water and were beginning to look soil starved.

Newly planted sweet potato slip.

Transplants struggle under the best of conditions, but hot and dry is the worst. Having the ground moist and workable again was perfect, especially with cloudy, cooler weather in the forecast.

I have a lot on my to-do list now, especially more mulching to keep the moisture from evaporating out of the soil. It's also a wait-and-see time, because some of my seeds seem to have been on hold while the ground was hot and dry. Hopefully, I'll have a thriving garden to show you soon.


Kristina said...

We are getting too much rain. I still have about 26 sweet potato slips to plant, and all my greens, carrots and beets. It's been a huge struggle for us this year.

Leigh said...

Kristina, I can empathize! Last summer we had constant rain too. It kept things cooler and well watered, but also made it difficult to work much in the garden. Not sure which is preferable - too much rain or too little.

Nancy @ Little Homestead In Boise said...

We have finally hit a dry spell after two consecutive Heavy Rain months. It's interesting the effect of the rain being sort of rained out once it gets on the other side of mountain. By I-84 the main Highway that runs across Oregon west to east when you hit the Hood River area it's really really Lush and green. As soon as you get past the highway that runs north and south heading east it's desert. That probably explains why. This intersection of the two highways is just this real clear division of Northwest forests with lots of rain and snow moving to Desert. Very interesting.

Ed said...

Unfortunately we've been drowning and the river is still in the moderate flood stage with more rain on the way this weekend. Wish I could share with you.

Fiona said...

That sprinkler hose combo rocks!

We just got much needed rain. Our clay soil is finally starting to show results from the addition of organic. My old farm was black loam and we got by with 12" of precipitation a year. It amazes me how this land needs ever bit of its 45" of rain per year. I enjoyed this post very much. It so explains how regions have variables that effect the climate.

Mama Pea said...

The challenge of working with Mother Nature and/or our particular plot of earth on this planet! Sigh. We continue to have temps that are much cooler than normal for this time of year. 46F degrees again this morning. Possibly hitting the low 70s some, but not many, days. Not complaining about the comfort level of these temperatures but the garden is not particularly liking it. Soil seems to be still too cool for the rapid germination of some seeds. Others pop through the soil but then don't grow without the warmth. But we keep changing and experimenting and trying, don't we!

Lady Locust said...

We've been dry over here too. Also, your explanation of soil building is as close to perfect as I can imagine. I took good soil for granted up the mountain. I had added back to it for so many years, I grew used to it. Now we are in a new place with neglected "dirt" that resembles cement. I am working on it like crazy, but it does take a bit of time. Oh, and your rainwater tanks have certainly earned their keep! Your planning and work are paying off:-)

Leigh said...

Nancy, it's interesting to see how landforms affect weather patterns. I think it helps to understand that, even though there isn't much I can do about it!

Ed, I'd take it!

Fiona, have you seen any of Gabe Brown's videos? He gets something like 11 - 13 inches of precip per year and has amazingly lush growth. He points to the soil microbiology. His videos are why I have hope. :)

Mama Pea, ain't that the truth! Even understanding the why of weather patterns, we're still stuck with their unpredictable variations. No wonder so many folks left farming!

Lady Locust, your soil sounds like ours - hard as concrete when it dries. It's a little easier to improve garden beds, but the pastures are a huge challenge. You are so right that it takes time.

Toirdhealbheach Beucail said...

I wish we had consistent rain from year to year. We never do: one year we can go almost all summer without a storm the next it rains every week. Right now we are in the latter; I have yet to have to water the lawn.

Leigh said...

TB, that's what's tough - not being consistent, and not being predictable. Makes gardening a challenge, doesn't it?

Rain said...

Hi Leigh :) Oh great idea with the watering can and the hose! That was an interested read about the weather patterns in your area. Thanks for that! I think we are getting too much rain lately, but at least we have a few snippets of sunshine here and there. Great job on the rain water collection!

Leigh said...

Rain, I wanted to get it watered quickly without having to keep moving the soaker pipe, lol. When it comes to weather, there's never a balance! Keeps us on our toes. ;)

Chris said...

Leigh, you just described our land's predicament. We can drive 20 minutes away, to luscious green land, that receives the rain we miss out on. On a micro-climate level, we're in a lowland pocket which blocks us from winds but also seems to capture the heat. Double rain deterrent, and increase the evaporation.

Luckily our main gully acts like a air-conditioner, and a corridor for wind to travel. Having said that, growing food in a gully with periodic water flow, has it's own problems, lol. I hope your crops are successful this year, amidst all the challenges. A case of rolling the dice, because even what you capture can run out. Which reminds me, we just got a storm recently, so I should go manually fill the small tanks up (from the house tanks).

Hopefully, installing guttering on the chicken coop soon, will change that particular exercise. ;)

Leigh said...

Chris, interesting! Landforms have such a huge impact on how a particular property reacts to wind, rain, and other weather patterns. Besides mountains, those low pockets are good examples. And you are so right about the unpredictability of gardening in such circumstances. Out of curiosity, from which direction does most of Australia's weather come?

Sounds like your rain catchment system is similar to ours. I have three 300-gallon tanks at the top of the garden, all of which must be manually filled from the big tank off the house. But I don't mind, and am thankful for the extra 900 gallons we can store.

Chris said...

Our land mass is small, compared to the USA, and we're located near some intense ocean currents - as well as being close to the Antarctic. So which direction the rain comes from the most, changes a lot. For our State (Queensland) however, we tend to get our storms during summer, from the north-east, or somewhere in between. Less so from the south-east.

When a storm system rolls in from the West, however, they tend to drop substantial amounts. I'm guessing it has to do with the Indian Ocean, on that side of the continent. There's also not a lot of mountain ranges on the West and central Australia. Mostly flat desert.

It's ironic, because we're actually closer to the coast on the eastern side of Australia. Yet have large mountain ranges which captures the rain, before it reaches us. But we're further from the Western side of Australia, yet because there aren't a lot of mountain ranges, we receive a lot of rainfall from that side. Unfortunately, rain from the West, is less likely, than the north-east!

My belated grandfather was a cattle man, and taught me if you see rain coming from the west - be prepared for it to stick around for a while. Which was probably the only "sure thing", when it came to rain falling on his property. The western rainfall (when it did fall - not every year) was the only certainty he had. If you wanted to reseed you pastures, that was the time to do it.

He also taught me, if you receive the first rains of the storm season, you will receive all the storm fronts in that particular season. If it skirted around your property early on though, chances weren't good for reliable rainfall that season. I've not found his advice, to fail me yet. I'm very fortunate he shared it, and luckily I haven't forgotten it, lol.

J.L. Murphey said...

Here too, Leigh. LOL
Even with watering from our rain catchment system, we lost 89% of what we planted. What with me healing from surgery and accidents, I was unable to tend the garden like I should have.The weeds have taken over 100%. I may just till it all under and put a thick layer of wood chips over the whole thing until spring next year...semi starting from scratch again. Sigh!