Wednesday, June 17, 2009

Water Garden

Monday, I mentioned the water garden located just behind the snake’s tail. Since a lot happens here and some of it will probably get mentioned in this blog, I thought you should be introduced to this obviously non-natural feature. I love dabbling in the water, but that’s an activity that’s definitely limited when you live in a xeric habitat. In order to satisfy my indulgence, I built an artificial pool, lined with a heavy plastic liner.

The basic size is 25 by 12 feet with a total depth of 32 inches. Why not deeper? Because 24 of those inches were chiseled by spud bar out of fractured limestone bedrock. I stopped excavating when I hit a layer that required either power equipment or explosives to penetrate. Around the edge is a shelf about 10 inches wide at a depth of about one foot. A pool like this is just what you want if you like wildlife right outside your door.

The pool is kept full by rainwater running off the roof. You can see the downspout outletting into the plastic tub with the attractive slap of brown paint decorating its outer surface. I’m still looking for just the right thing to replace that tub. The tub catches debris from the roof and keeps it from entering the water garden.

From the tub, some water is diverted into the pool seen in the foreground. This is a 100 gallon stock watering trough that houses pet goldfish during the summer. The overflow from the goldfish pool enters a drain that outlets in the front yard and does not enter the main pool. I wanted the main pool to develop its own natural ecology and didn’t want to take any chances of it becoming full of goldfish.

The water headed for the main pool passes into a small, shallow pool as it leaves the tub. This pool catches any debris that happens to make it out of the tub and helps to dispel the energy of the running water so it has a more docile entry into the big pool.

I’ve tried to introduce native plants found on the property to this artificial habitat. This Field Horsetail, Equisetum arvense, was brought up from the creek. It was planted in a small area with a plastic liner intended to keep the plant from getting out of control. OOPS. It’s on the run now and hasn’t responded to my verbal suggestions that it stick to its designated area. Looks like I’ll have to take a more active approach here.

The water lilies were purchased from the local discount store. I know it’s not native to this site, but there’s no place for it to go if it does escape and I’ve always wanted a pool with water lilies.

This is Small-Flowered Water Plantain, Alisma subcordatum. It used to grow in a small pond near the house. This plant couldn’t survive the increasingly erratic water levels in this leaky pond, and is no longer found there.

Most of our guests see the water garden and immediately think mosquitoes. No chance of mosquitoes when the predatory larvae of insects such as these damselflies are present.

Another super aquatic predator is the larva of the dragonfly. Several dozen of these skins appeared overnight. Apparently we’ve had metamorphosis of the nymphs into flying adults.

An adult Blue Dasher dragonfly. This dragonfly is a little too small to have come from the preceding skin. The wing veination is fairly easy to see in the shed skin, so maybe a little investigation could tell us what species it represents.

Some adult Water Striders have found a meal of tree frog eggs stranded on top of a water lily leaf.

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