Thursday, June 18, 2009

A Closer Look: Watering - Rain Rain

Tsukuzuku to
noki no shizuku o
hi o nomi kurasu
samidare no koro

Staring blankly
at the drops
from the rafter ends,
barely getting through the days -
fifth-month rainy season


Samidare wa
iwa seku numa no
mizu fukami
wakeshi ishima no
kayoido mo nashi

Rock-damned marsh-
in fifth month rains
so full of water
you can't pick your way
over the stones any longer


Samidare wa
yukubeki michi no
ate mo nashi
ozasa ga hara mo
uki ni nagarete

In fifth month rains
no trace of a path
where I can make my way,
meadows of bamboo grass
awash in mud


Saigyo, one of my favorite poets, seemed about as irritated, yet resigned, as I am about the rain. Though June is the sixth month of the Gregorian calender, in times past (Saigyo was born in 1118 CE, in Kyoto, for the curious) Japan's fifth month ran from around the middle of May to the middle of June. And Japan's fifth month, was of course, the rainy season.

Here on Long Island, we don't have a rainy season. Yes, like many places, it rains more in the spring than other times..... but this.... this is not typical. It has rained six out of seven days a week (or more) for the last five weeks. Some days it has only showered briefly, but other days (like today) it has just poured down buckets all day long.

This is a problem. Don't get me wrong, my garden is *loving* all of this rain. It is so happy right now if they could, the plants would get up and do the watusi. However, as has been stated over and over again by many, many bonsai enthusiasts... a pot is not the same as the ground. And my bonsai are a little dubious of all this rain.

I can already hear the question, "well, don't you have a good, free draining soil mix? What's the worry?" I *do* have a free draining soil mix. It's great, and I haven't had any issues with root rot, well, ever, but that's as much from watering correctly as it is from the soil mix. You *can* over water, even with a free draining mix, it's just a lot harder, and most people won't be out there, soaking their trees six or seven times a day in my climate.

But the worry is related to that, in its way. The soil never getting a chance to even partially dry out. I repotted a lot of trees this year, including several from over grown nursery containers where I had to put a lot of stress on their roots just to sort out the mess. Let's say that easily a third of my trees are, this season, on sub par root systems, for one reason or another. So what do I want from those trees this season? I want them to grow roots! Lots and lots of roots. But see, here is the problem.

When roots are always wet, they don't need to grow as much to get the water they need. It's all right there! This is noticeable on Jade trees you might have indoors. You can't even get a cutting from one of those suckers to root unless you let it dry out a little. Jades put out roots in response to low water situations. A lot of trees are like this, only it's not so obvious as Jade cuttings that'll sprout roots in a day or two under the right conditions. Ever wonder why they tell you to water lightly after a tree has been repotted? Many people cite that it is because the tree doesn't need as much water, and the roots can't take up as much water, since they've been pruned, and you might rot out the roots. This is half of the story. It's also because if the roots are kept soaking wet, they don't need to *try* to grow. The plant tells itself "there is plenty of water coming up here, we don't need to release hormones that will make the roots grow. We're steady in this pot (they put wires on us for that), so between stability and a readily available source of water (we'll worry about nutrients later), we're good to go!"

So, where does this leave me? Trees that I would have watered sparingly (plenty to keep them alive, just not like this, sheesh) are getting soaked and staying soaked.... every day. So root growth has slowed down considerably. Ok, again, what's the big deal? So the trees need an extra year to recover, right? Maybe, but for different reasons than just improved rootage.

Michael Hagedorn commented on what is going to be my problem in a month or so on his blog,

Before the real summer heat hits, consider how you are watering your
Have you ever seen your trees grow through spring just fine,
only to get fried leaves at the first onset of early summer? Ever wonder why
that happens?

Those trees just don’t have enough roots. Those are the trees that got
overwatered, or simply never dried out, in the cool spring months. Their roots
were never encouraged to hunt out water, so these trees could survive in the
moist cool weather on about three roots. First hot day: bam, they get hit hard
as they have a spindly root system, not enough to support their overlarge, over
long leaves and shoots on dry hot days. (A bonsai version of a company that has
overspent just before a recession…)

Especially on cool overcast days, if you can monitor them, water each
tree only when it is really drying out and not by rote. Watering by a schedule
is the surest way to have some really weak trees that show themselves in the hot

I discovered this the hard way two years ago, when I thought I was doing my newly repotted trees a favor by giving them extra water to make it easier on them. And, as Michael said *bam*, first hot day, bad news. At the time, I knew the trees weren't getting enough water to keep the leaves from burning, but why? I watered them, plenty! I just didn't know. It took me a couple months and *a lot* of reading (in some very heavy botany books) to figure out what had happened, and why those trees, that had seemed so healthy, that I had been watering (what I thought) was correctly, had ended up like that.

It's just like kids. Making everything easy for them doesn't encourage them to grow. They have no reason to. I'm not saying kids (or bonsai) need to be thrown to the wolves- but a little hard work never hurt anyone.

So in July and August, I can pretty much count on most of the trees I repotted and did serious root pruning on this year having trouble. Too much heat, not enough roots, so not enough water getting up in to the leaves. This, beside the obvious unsightliness, is more importantly an issue because of the stress these trees will be under. Stressed bonsai are more susceptible to disease, pests, die back, and a host of other issues.

If the roots ain't healthy folks, ain't nothing healthy.

There is, unfortunately, little I can do about it at this point. Those trees that were repotted have been placed under bonsai benches and generally shaded from the worst of the rain, but with the humidity so high, the soil is still unable to dry out. When the rain stops, and it starts to get hot, these trees (especially those that I know already have the weakest root systems) will continue to be protected, especially from the sun in the hottest part of the day even if I wouldn't have normally worried about them. These trees will get a changed fertilizer regime, lowering the amount of nitrogen, but keeping the phosphorus and potassium at the same levels. This will help keep the amount of foliage that the roots need to supply with water to a more manageable level (lower nitrogen), but still encourage root growth (phosphorus).

Hey, I said I didn't want to throw them to the wolves, didn't I?

In Japan, watering is considered an art in and of itself, and some apprentices are at a nursery for two or three years before they are even allowed to touch a watering can. I'll be honest, I'm not certain I should be allowed near the hose myself.

But I'm learning.