Spring has sprung, leaves are budding, and flowers are in bloom. Whether you have acres of land or a patio with a few containers, it is time to think about what you’ll be planting and watching grow. This season, give your plants the best start by improving your soil with compost.  After all, healthy soil makes healthy plants!

Compost improves soil

Compost is dark and crumbly, smells like the earth and is loaded with beneficial microorganisms. It is created when organic materials like leaves and food scraps decompose with the help of microbes that need oxygen to thrive. Compost can be made in many places - backyards, community gardens, and industrial compost facilities.

Mixing compost with ordinary soil provides many important benefits, like its ability to hold nutrients and improving plant vigor. Compost also helps conserve water, prevent erosion, reduce greenhouse gas emissions, and grow healthy plants that are more likely to resist disease.

It’s easy to get started building healthy soil for your landscape or garden by first learning what type of soil you have. You can do a simple squeeze or ribbon test to learn your soil’s structure and texture. Adding compost helps sandy soil hold water, an especially helpful quality during drier months. If you have clay soil that does not absorb water very well, adding compost can help water infiltrate the soil. 

Compost improves the efficiency of fertilizers by holding them in the soil instead of allowing them to run off with each rain. Compost has some plant nutrients itself. When compost is made with food waste or manure, it typically has more nitrogen than compost made with mostly woody material. If the compost that was made with more wood it can be used as a mulch or soil topping instead of being tilled into soil.

Whether applied on top or mixed in, compost is an investment in healthy soil, plants, and yards.

Purchasing Compost is okay

Buying compost is a great option if you need more than you can make. Remember to first consider how much you will need. The User’s Guide to Compost shows how to calculate the quantity of compost needed based on the project.

Compost is sold in bags or in bulk. Both options have their advantages. If you need a small amount, check out home improvement stores or garden centers for bagged varieties. Some grocery stores will stock smaller quantities of the product early in the season. Bagged compost is typically high-quality and easy to transport where you want it. 

When you need a large amount of compost, buying in bulk can save time and money. This is usually less expensive than buying the same amount in bags. Be sure to ask about delivery fees. 

Ask retail yards and compost facilities if they have compost available for sale. You can also check with your local compost or soil blending facility to learn more about the product before you buy. When speaking with the salesperson, ask about the material used to make the compost. You can even ask for test results! This can be important if you want to steer clear of false advertising of material that isn’t compost or doesn’t have compost in it. It’s also helpful to know what material went into making the compost. If you are interested in compost that has higher nitrogen content, which for example could have been made with manure or food waste. 

The more you know about the compost, the more you can understand its quality and how to use it.

Learn how to make compost and vermiculture

These organizations offer classes and online resources on composting and vermiculture (worm castings, aka worm poo):

• Tilth Alliance - classes
• WSU Extension Master Gardener Program  
  Some of the WSU Extension Offices offer Master Recycler Composter Programs, including Thurston and Clallam County. Thurston County offers free online composting workshops to everyone.
• Washington State Department of Ecology’s Compost page has a list of composting resources for residents, businesses.

These websites have information on how to make or purchase compost and vermiculture bins:

• WSU Master Gardener Resources 
• Washington State Department of Ecology - Compost
• USCC Compost Resources
• WSU Extension Backyard Composting (Home Garden Series)
• WSU Whatcom County Extension Office’s website has some examples of compost bins. They also have instructions on how to build a worm bin out of a plastic storage box, a larger wooden worm bin, and a three-bin compost system.