Coping with Heat & Shohin

Just thought I'd pose a quick question to see how others do it. How do you help your shohin through heat waves?

I have set my trees on trays/tubs filled with sand & allowed them to root into it. Thats worked well for me. Takes up a lot of space though.

I have heard of others using carpet pieces....has anyone tried this? I suppose it works somewhat like capillary matting.

Thanks for your input.

Neil

Hi Neil. What sort of temperatures are you talking about here?

We have had a fairly hot last three weeks (anything between 15 and 25C but little or no rain and not dropping below about 9C overnight) and my shohin have needed watering twice if not three times a day. I have them on benches on a south facing side of the house. They get shade from the full glare of the sun form a rose pergola and this probably takes the sting out of the heat during the warmest part of the day.

I am currently fortunate enough to be in a position where thrice daily watering is possible. So far I have not had to resort to anything other than this but have a large roll of capillary matting in the glasshouse which is rolled under the trees if I am away for even so much as a weekend.

I suspect the only foolproof method is water, water and water again.

And yes, I am also aware that there are those out there who are blessed with wall to wall sunshine and who are putting on extra sweaters and filling hot water bottles at the very thought of anything as cold as 15-25C. Lucky b******s!

Hi Neil. It gets pretty hot here in Dallas too, and it's supposed to hit 101 degrees here this weekend (38.3 Celsius). I have been soaking long-fibered sphagnum moss in a bucket of water, and then applying it when it is going to get super hot. Even that wasn't enough last year watering twice a day, so now I'm thinking about a new approach. I'm not familiar with capillary matting, but I guess that depends on the mat contacting the growing medium from underneath. Is that correct? I heard a couple guys at the BSD club auction talking about a wicking system, but I assumed that it was to be set on top of the soil. I kinda pictured a setup with multiple buckets of water with cords or swaths of wicking material (cotton, nylon...?) coming out and circling on top of the pots. Would that even work? I would like to hear if anyone has any good tips on wicking/capillary watering.

One solution is to take cotton or linen wick material and thread it up into the pot through the drainage holes and allow the wick to sit in the evaporation tray. You might need to do more than one. This will immediately serve to provide a water source to the plants instead of waiting to grow roots.

I think I found an article using this, I will try and find photos.

Jay

I have about 20 little trees, each of which will sit on the palm of my hand -- sometimes 2 to a hand. I rely primarily on watering twice a day. So far, the hottest we've gotten here is 92 degrees F (51C). But I also rely on the soil in the tiny pots. In most (but not all) cases it is 70-80 % organic material (decayed bark) and 20-30 % Turface (or cat littler for you European types) -- the reverse percentage from soil in large pots.

In winter, I bury them in that mulch in a shallow tub and let rain or snow do the watering.

JimLewis wrote:I have about 20 little trees, each of which will sit on the palm of my hand -- sometimes 2 to a hand. I rely primarily on watering twice a day. So far, the hottest we've gotten here is 92 degrees F (51C). But I also rely on the soil in the tiny pots. In most (but not all) cases it is 70-80 % organic material (decayed bark) and 20-30 % Turface (or cat littler for you European types) -- the reverse percentage from soil in large pots.

In winter, I bury them in that mulch in a shallow tub and let rain or snow do the watering.

Jim, that would be around 33C not 51C...51 would be a bit on the toasty side.

Mike

I double pot by sinking the small pot in a larger pot full of the similar free draining soil I habitually use so that the surfaces are flush. A trip from Chris Johnson iirc.

This gives an extra volume of soil and moisture around the smaller tree.

In a few weeks any escaping root growth can be trimmed off and the tree has also had a chance to expand a little I guess.

When I go on holiday, I sink my dozen or so tiddlers in a slatted box made from a pallet full of bonsai soil -same thing as above on a larger scale. The box is lined with plastic punched full of holes for drainage.

A good soak and it will last for 4-5 days easy which takes the strain off the stand in watering crew.
Thks

TimR

Jim, that would be around 33C not 51C...51 would be a bit on the toasty side.

Well! So much for THAT conversion program!

Thanks for the ideas guys. I may give the Kathy Shaner idea a shot on a couple of trees. Shag carpet remnant to set the little guys on. This would do much the same as capillary matting.

Another thing I have used in the past and plan to use again shortly is Dyna gro Pro tekt. This stuff is a 0-0-3 and has a high amount of silica. It turns the leaves into green leather and the heat tolerance is very good.

Gonna be HOT today...triple digits 100F. My shohin quince suffer the worst. You can almost here them out there whinning about the heat. They stay under the bench in the shade in a tub of sand where the roots run into.

Great thread. Thanks, Neil.

You have something which works (trays of sand) & that is a huge advantage for transitioning to something more convenient recommended by a reliable source (Kathy Shaner's carpeting). Did Kathy recommend the carpet very densely contact drainage holes-- turning them from primarily drainage to primarily water source? In the heat, will the major drainage be evaporation?

Still, the plant including leaves should be watered from above & from below (flipped) for cleanliness and to retard insect damage regularly.

Soil choices, dryness of the environment, air flow & access to light must affect this a great deal as well as differential draw of water for among plants. Age & strength of the plant as well as recent changes in location can affect watering.

My experience with small bonsai is modest... but the subject is as fascinating as their horticulture is demanding.

In Cyprus, where i live, last year we had water shortage and water supply was interrupted. We had water supply every other day..... I managed to keep my trees alive in the heat (July and August the temperatures may rise above 40-42 Celsius). I used big plastic shallow pots, lined with sphagnum moss and i placed the small trees in them and then covred the space between the pots and on top of the soil using sphagnum moss. The big pots were then placed in a shady place
This way, I managed to have enough humidity and keep the trees alive, even though the temperatures were extreme and the shortage of water made everybody's live a hell.

JimLewis wrote:

Jim, that would be around 33C not 51C...51 would be a bit on the toasty side.

Well! So much for THAT conversion program!

I've had worse Jim. I tried a conversion to speak with a Japanese Bonsai enthusiast, which was hopeless.

Mike

Stavros,
That must have been awful. I'm glad you found a creative solution that worked for you!

Chris,
Not many details on the Kathy Shaner recommendation. I saw it in an issue of Golden Statements (GSBF newsletter). It sounded like it may work very well.

I'll do some experimenting this summer. My shohin are mainly trident and elm. Both of which root much differently in the sand trays. The elms seldom need to root into the sand while the tridents do so vigorously within a few hot dry days.

Either way..I set up my sprinkler, and timer today. Something I did last year was to use a 2-3 inch layer deep flooring of haydite all over my growing area. It provides great ambient humidity during Tulsa's hot summer. The worse part is not the heat as much as the dry hot southern winds.