I was very impressed by the “leaky hose system” described by Wayne Schmidt (scroll a bit down the page). It sounded like a fine system but more work than I really wanted to put in. However, when I priced out soaker hoses (about $11 per 10-foot length), I decided it might be worth it to try Wayne’s idea. Also, I had worked with PVC to make a bird netting enclosure for my strawberries, and I was impressed with the ease of handling PVC pipe, and all possibilities afforded by the cool connectors.

Wayne does a good job outlining the basics of his system: “I drill two rows of 0.038-inch diameter holes six-inches apart at a 90-degree angle down the length of a 3/4-inch diameter PVC tube.” On the bottom, he drills another set of holes 4-feet apart for drainage when the system is off. So far, so good.

My first problem was finding the “micro drill set” he mentions. The smallest drill bit I could find for a standard drill was 1/16″. The guy at Lowe’s looked at me funny when I asked for a “micro drill set”. But he did point me to a set of drill bits for a Dremel, which included 1/32 and 3/64, both of which are smaller than 1/16. 1/32 works out to 0.013125, which is a tad smaller than required. Little did I know, in order to use the tiny drill bits I also needed a Dremel Quick Change Collet Nut Set, which necessitated a second run to Lowes. Ah, well.

The big mystery to me was how to connect the PVC system to my standard household hose. I did discover threaded attachments for the 3/4-inch PVC. To make a long story short — I spent over an hour in the store figuring this out — below is a diagram of my setup.

My irrigation system: Click for PDF.

Drilling the holes was a bit of a pain. I basically decided to draw lines down the length of the pipe, kind of “eyeballing” it with a pencil and 24″ ruler to make a straight line. Then, a second line about 90-degrees off from the first. This is made slightly easier by the fact that my work surface was a wooden deck; I placed the PVC into a groove in the deck to keep it still. Placing a male adapter on the PVC pipe helped a bit, too, as it has an octagonal reference surface on it. As long as the octagon was laying flat, I could pretty much get a good pair of straight lines, 90 degrees apart.

Finally, in the garden. I get beautiful results, as long as the pipe is laid more or less parallel to the ground. The little stream of water is perfect, not too harsh and not too slow. I can even space my holes to match the spacing of the plants in the row.

Update March 2010: After using my drip irrigation system for a season, and also using some soaker hoses elsewhere in my garden, I have to say I far prefer the drip irrigation. You can more easily see and therefore control the water flow with drip irrigation. I had better visual feedback and therefore more confidence that my plants were getting adequate flow. Another thought: the drip irrigation works best in a long garden that’s divided into two rows of plants, with the PVC going down the middle. Finally, the PVC is kind of a pain to store; I wound up leaving the pipes exposed outdoors, and I’m not certain what kind of shape they are in now. Ideal storage would be a garage or similar.

That’s the great thing I’m learning about vegetable gardening. Everything is kind of an experiment, and there’s no one “right way” to do it. I’ve consulted two books this year, Square Foot Gardening and Joy of Gardening. Both have slightly different advice to give about planting density and methods. Joy of Gardening, in particular is pretty hard-core about using methods to extend the growing season and getting more yield. “If you’re not losing a few plants to frost,” says author Dick Raymond, “you’re not putting them out early enough.”

I don’t think I got things out early enough to satisfy Dick. I had to prepare two brand new beds this year, and my order of seed potato didn’t arrive as soon as I would have wished. But I caught up this week, and now I’m right about where I want to be:

Sprouted indoors, transplanted outdoors:
Brussels Sprouts (9; might go for a few more)

Sprouted Indoors, hardening off to plant next weekend:
Tomatoes: three or four varieties!
Basil
Pumpkin (2 really big plants)

Sprouted Indoors, will harden off later in May:
Sweet peppers
Hot peppers

Planted outdoors:
Red Onions: my first time
Carrots
Radishes
Lettuce
Chard
Spinach: my first time growing spinach
Potatoes (last week); my first time growing potatoes!

Just sprouting now indoors: for transplant in a few weeks
Melons (sprouted on a wet towel, now in peat pot)
Red Onions
Pumpkins
Lettuce