savvy classes: classes resuming in September

editor's note: less hose dragging and longer harvests

feature story: getting started with drip irrigation

savvy advice: extending your food growing season

Our classes will resume in September with wildlife friendly gardening, shrinking your lawn and adding fall color.

Summer arrived surprisingly early this year! If your goal is to lounge in your back yard or play with family, then you might be searching for convenient and efficient watering strategies. Drip irrigation offers many advantages over both soaker hoses and automatic sprinklers. In our feature story, we answer common questions about drip, describe key components, and help you get started.

Summer warmth also brings a delicious harvest of homegrown fruits and vegetables. To continue the bounty into fall and winter, read our expert advice from Seattle Tilth’s Katie Pencke. The bonus with fall and winter crops is that you won’t need to spend time watering when rain returns.

Do you have a friend who needs help using water efficiently? Send them the link to the KING5 News story with five simple watering tips. Or share our expert advice on watering strategies from the Summer 2007 Savvy Gardener.

Getting Started With Drip Irrigation

As the most effective way to water most plants, a drip system conserves water and saves money and time.

What is drip irrigation?
Drip irrigation uses flexible plastic tubing with tiny holes or “emitters” that slowly release water into the soil.

What are the benefits of drip irrigation?
Unlike typical sprinklers that waste a lot of water through evaporation, runoff and overspray, drip irrigation delivers water directly to plants’ roots. As a result, drip irrigation is not only more efficient, it’s also healthier for most plants.

What is the difference between drip and soaker hoses?
Soaker hoses also water slowly, but they are designed so that water leaks all along the hose, whereas drip tubing has individual emitters delivering precise amounts of water at specific intervals. Also, soaker hoses don’t work well on slopes, but pressure-compensating drip emitters deliver the same amount of water regardless of changes in elevation or the length of the row.

Is drip for you?

Drip works best for. . .

• Slopes
• Food gardens, where you may not want to use soaker hoses, which are typically made of recycled tires (and may contain toxins)
• Ornamental beds, especially where you would need more than 200 feet of hose (soaker hoses should be no longer than 200 feet)
• Containers that need frequent watering

Drip might not be the best choice for. . .

• Watering your garden beds infrequently—it may be simpler to use a hose and sprinkler or a watering wand.
• Establishing a small area or a few trees that you will rarely water after two or three years. For small areas, a watering wand may be easier; for individual trees, you can use a watering bag.
• Watering lawn, which is better suited to overhead sprinklers. However, you can set up underground drip for turf with more planning.

What to consider when choosing a drip system

Types of drip emitters

• In-line emitter tubing is the simplest to install and the best-performing type of drip. It will work in small and large gardens and in a variety of configurations. The pre-installed emitters are self-cleaning and won't snap off if stepped on, plus you won’t have to hand-punch each emitter. Be sure to get the “pressure compensating” type.
• Microtubing (or “spaghetti tubing”) also comes with emitters pre-installed. Works best in pots or food gardens where you may reconfigure the layout annually. Avoid laser type or 1/8-inch lines.
• Punch-in emitters come in many shapes and sizes. While they are the least expensive, each emitter must be punched in by hand and may need cleaning to prevent clogging.
• Micro-sprayers or bubblers are better suited for highly arid climates. They get leaves wet which can cause diseases in the Northwest.

Factor in time to plan
You’ll need to know your water pressure, flow rate, type of soil and water needs of your plants to understand how large your system can be, how to space your drip lines, and how long to water. Sketching a drawing of your drip system will help you know how much tubing and how many fittings to buy.

Can you do this yourself?

Yes, you can. Our Drip Tips factsheet (pdf) shows the planning steps, explains essential parts, lists equipment suppliers and gives tips on maintenance. Also check out the Savvy Finds Publications listed to the right.

If your garden is very large, you may want to get professional help. When choosing irrigation contractors, ask about their training and experience installing drip systems. Some contractors understand the best types of drip systems for different situations and how to set them up, while others specialize in underground pipes and automatically controlled sprinkler systems.

Where can you buy parts for a drip system?

• Specialty irrigation suppliers carry all of the parts you need. Keep in mind that they mostly sell wholesale, so they may have to serve contractors before they can help you; a few are open on Saturday mornings, when they may be less busy.
• Nurseries, hardware stores and home improvement stores might not stock all of the parts for the “head assembly”—call ahead to ask. Make sure they carry backflow prevention devices, which are required on all drip systems, as well as pressure regulators.
• Web sites also sell drip parts. If you ask for assistance from an on-line retailer, be sure they know you live in western Washington because we have different watering requirements than more arid states.

Katie Pencke is the Seattle Tilth Demonstration Garden Coordinator with eleven years of teaching experiential education and managing public landscapes.

Extending Your Food Growing Season

Here are key steps for conserving water in your summer food garden and planning ahead for fall and winter.

Mulch Now
In the spring, you want to let your garden dry out from the winter wet. By early summer, you should mulch vegetable beds with organic straw, composted leaves (leaf mold) or grass clippings to help soil retain moisture.

Plant Now for a Bountiful Winter Garden
With a little planning now, you can enjoy homegrown vegetables throughout the fall and winter and into early spring. Winter gardens have the advantages of being low maintenance and water efficient because they don't need supplemental water once the rains start and pests and diseases are much less common.

• Root Crops: Sow root crops like carrots, rutabagas, and beets in mid-July. They can grow to maturity by the time the weather cools down in the fall. Keep them stored in the ground where they grew. They’ll get sweeter with colder temperatures. You can harvest throughout the fall, winter and spring.
• Cabbage Family Plants: Start large cabbage-family plants (Brassica) like broccoli, kale, cauliflower and cabbage by the end of June. These starts can be planted out as late as the second week in August, or later if you use row covers to insulate the plant starts. Fast-maturing varieties will be ready for harvest in the fall and winter. Overwintering varieties like purple sprouting broccoli will be ready for harvest in the early spring.
• Salad and Cooking Greens: There are still many options for planting fall greens. Lettuce, endive, chard and spinach can be sown July through September. Parsley can be sown in July; mustards, cress, cilantro and chervil can be sown in August and September. All of these will grow a bit faster and longer into the winter months if you place a cloche over them when cold weather begins in late October.

Protect and Build Your Soil
If you are done with food gardening until next year, use cover crops or mulch to add nutrients and prevent soil compaction, leaching of nutrients and weed growth over the next several months.

• Cover Crops: Sow crimson clover as late as September, winter rye as late as early October, or fava beans as late as early November. You will chop them back into the soil in the early spring, then wait three to four weeks for them to decompose before planting or seeding. These crops will block weeds and add nitrogen to your soil as they mature.
• Mulch/Compost: Cover the garden bed with fallen leaves, disease-free crop residue, grass clippings, straw, or shredded newspaper. Top with a burlap sack to keep it all from blowing away. This compost pile will serve many of the same functions as a cover crop.

Learn More

• Got a gardening question? Ask the experts at the Garden Hotline: (206) 633-0224
• Classes: Seattle Tilth offers a wide range of classes for adults and children
• Publications: see the Savvy Finds Publications to the right.

For free garden advice and information, please contact the Garden Hotline at (206) 633-0224 or help@gardenhotline.org or visit www.savingwater.org.

We welcome your suggestions. Please share them by emailing Liz Fikejs, Seattle Public Utilities.

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Photo and garden credit: Top left photo of chair in garden by Stacie Crooks Garden Design.