September

Willamette Valley, Oregon, USDA Zone 8b

September, how do I love thee? Let me count the ways.

1. Your nights are cool, allowing me to get cozy.
2. Your evening breezes refresh my soul.
3. Morning work in the garden is pure pleasure.

The summer harvest frenzy should begin to slow down this month. Hopefully your cool-weather veggie starts are growing well. They can go out as space opens up. Also, let’s start thinking about harvest storage, garden cleanup (or not), and winterization plans. 

Warmth Loving Crops 

September is usually the last hurrah for these warmth loving plants. When temperatures begin to drop below 50 degrees at night, it’s time to call it. First, pick the remaining fruits. Then cut the vines at soil level. Lastly, chop and drop their vines and leave them on the bed to return their nutrients to the soil and feed the microbe community.

Nightshade Family🍅🍆🌶

• Tomatoes. If there is even a tiny bit of red-orange color they can ripen. If not, enjoy some fried green tomatoes. Try cutting the plant at the base and hanging upside down in a sheltered indoor area and see if they will vine-ripen. Keep out of the fridge. Tomatoes ripen best when in a temperature range of 65-70°.
• Eggplants 
• Peppers 

Cucurbits🎃🥒

These guys might start showing signs of powdery mildew. You can spray a 50% milk and water solution to help slow the spread, but it’s also OK to do nothing. It happens like clockwork this time every year. Drop diseased vines in your yard debris bin, unless you can get your compost cooking at 135-160° for three days.

• Cucumbers
• Zucchini
• Squashes
• Melons

Fall Crop Planning

Transplanting Tips

The second half of September is ideal for transplanting cool-tolerant fall crops. Make sure to work in a nitrogen rich fertilizer as fall soil is generally depleted of this important nutrient. 

Direct Sowing: There is still time to sow:

• Carrots (Light on the fertilizer for these guys. Keep soil moist until germination.)
• Cilantro
• Onion (An overwintering variety, harvest late spring or early summer.)
• Garlic – Harvest will be next July.
• Radish
• Spinach
• Turnips

The Rain Returns🌦

Reliable rain should begin to return around the second half of this month. We average about 1.5” in September. Keep an eye on your Weekly Watering Number and read Six Ways to Water your Garden for more tips.

To Clean Up or Not to Clean Up?

As your August jungle plays out it’s tempting to just rip it all out and get tidy. Consider only removing as much debris as is necessary to make way for your fall crops. Otherwise, here are some options that save you time and room in your yard debris bin, while protecting your soil and feeding the soil ecosystem.

1. Chop and Drop: Chop your spent crops to the soil line using a hoe or pruners. Then cut a few times with your pruning shears (or not) and drop on your bed. Benefits:
   1. Activates insects and microbes to do the work of decomposition to return the nutrients to the soil.
   2. Leaves roots to rot in the soil, which feeds microbes and creates pore spaces for microbe habitat, water storage, and air pockets. (Helps create good soil structure.)
   3. Protects from rain. Unprotected soil becomes compacted and leached of important minerals. 
2. Leave crops to finish flowering and going to seed. (This looks messy but provides insect habitat, which provides food for beneficials, as well as food for pollinators and birds.) 
3. Sow Cover Crops: Chop to the soil line then broadcast some winter cover crop seed to enrich and protect your soil through the winter. Some good choices are winter rye, fava, Austrian field pea, daikon radish, and winter oats. My favorite is a cold hardy mix from True Leaf Market.  (Only use if you will be ready to terminate it in late winter/early spring. Cover crops can be weedy if left to mature.)

Exceptions: As much as I love to capture nutrients and return them to the soil, there are some things that gotta go in the bin and off the property. Unless you are a composting guru and can get it hot enough (135 – 160° for three or more days) to cook the pests and disease.

1. Diseased foliage. My cucurbits always get powdery mildew late in the season.
2. Diseased and rotten tree fruits and cane fruits. These attract unwanted pests and help perpetuate their life cycle. 
3. Fruit tree leaves go too. Many fruit tree pests and diseases overwinter in leaves. 
4. Weeds with seed heads. One year of seeding means seven years of weeding as the mantra goes.

Seed Collecting and Saving

Want to feel like a garden expert? Try saving your own seeds. Some super easy ones to start with: sunflower, nasturtium, calendula, garlic, potatoes, and spinach. Collect, spread out on a tray, screen, or cardboard flat to dry thoroughly. Then label and store in your refrigerator. Read my Seed Saving Primer for more tips and tricks. 

Crop Storage

Check out this article for my favorite methods of crop storage. 

🍂Fall Leaves: Don’t let this important resource go! Use them to:

• Start winterizing your beds.
• Build a leaf mold pile. It takes two years for leaves to breakdown into leaf mold, but this stuff is amazing. Read more in this mulch article.

Winterizing Your Garden

The only wrong way (I know this from experience, sadly) is to leave your garden soil bare all winter. The rain will compact the soil and leach out important nutrients and minerals. It will take significant effort to get your beds in shape for spring planting. Instead, put your garden to bed for the winter by following these easy steps and your soil will be ready to welcome your spring starts with minimal effort and adjuncts.

Lawn Care

• The 3rd fertilizer application in our Greener Grass plan is due around Labor Day. Read more in the Turfgrass Growing Guide.
• Irrigation needs will begin to taper off this month. Continue watering early in the morning. Check your weekly watering number on the regionalh2o.org website.  Read Six Ways to Water Your Garden & Landscape for more tips.
• Cut your grass on a high setting so it is at least 3″ tall after mowing. Taller grass keeps the soil cool and moist, shades out weed seeds, and promotes deeper rooting to bring up water and nutrients.
• Use the mulch setting. Lawn clippings break down fast and recirculate nitrogen into your soil reducing the need to do more fertilizer applications.
• If you are re-seeding or have seedling grass, keep soil moist. It may require afternoon water on warmer days. The root system for seedling grass is very tender and shallow and needs consistent moisture until it is established.
• Spread compost or add a dusting of lime.
• Want more tips for growing grass that is green in all senses of the word? Check out the Turfgrass Growing Guide.

Wildlife Care

Birdbaths: Scrub and flush at least once a week to prevent algae and spreading diseases .

Bird Feeding: Suet is a great way to provide energy through the cooler temperatures of fall and winter and creates minimal mess to attract rodents. If using a seed feeder, get the good stuff. Birds are choosy and will fling out what they don’t like. Then mice and rats will clean up the discarded seeds and maybe set up camp under your house. I put out black sunflower seeds in a tight cylinder feeder. I also bring the seed feeders in at night.

Hummingbirds: Some of our Anna’s hummingbirds overwinter in the Willamette Valley. Our nectar feeders can help them make it through until spring. Clean and refill at least once a week. I have a glass feeder and like to pour the nectar in while it is still very hot to help sanitize the feeder. Then I set it out once it has cooled. An extra set of flowers will allow us to swap them out and run the dirty ones through the dishwasher. 

Bugs and stuff: Leave the leaves, wherever you can. (Except in the fruit orchard–those ones have to go.) Cover your beds and bare soil with fall leaves or and compost. Leave flower stalks and seed heads and such until early spring. Most of our insect friends overwinter in the soil and hollow stems and leaves as larvae, eggs, or in their adult form. They need shelter and food and will thank you by coming back in large numbers in the spring. (E.g., as soon as the aphids show up–I find ladybug eggs and larvae everywhere.) I always leave spider eggs sacs too. Spiders are voracious consumers of pest species.

Feeling guilty? If you’re feeling bad about leaving your yard messy for fall and winter, read this article from the Audubon Society and you will feel much better about it. To Help Birds this Winter, Go Easy on Fall Yardwork.

Happy Harvesting!  

Hope your dehydrator is blowing, your canner is bubbling and whistling, and your kitchen looks like a hurricane blew through it. BTW, if you’re wondering if I’d like a sample of your homemade salsa. Yes. Yes I would. 

Simple Harvest Storage Techniques

Further Reading

• OSU Extension: Grow Your Own Tomatoes
• Seed Savers Exchange: Seed Savers Chart
• OSU Extension: Collecting and Storing Seeds from your Garden
• Washington State: Compost Fundamentals
• Yellow Garden Spider