September is when your garden starts making the transition from summer to fall. The days remain warm, but cooler nights are coming, and the soil is still optimal to get a new crop established.

If you have an empty spot after pulling out tomatoes, beans, or summer squash, don't leave it bare. September is a great time to plant vegetables that will carry you into fall and, in some cases, through the winter.

One of the best September crops. Sow directly in the garden and keep the soil consistently moist while seeds germinate.

Lettuce, endive, mustard greens and other quick-growing greens are good choices. A little protection can extend the harvest as temperatures drop.

September is a good time to try fall peas. Give them a sunny location and something to climb.

Plant fava beans now for an early-season crop next year. They're particularly well suited to the Pacific Northwest.

Cooler weather is much kinder to these herbs than Portland's summer heat.

September is also a good time to get garlic and shallots started. Plant individual cloves in well-drained soil, pointy end up, and cover with a few inches of soil.

If you have an area of bare garden that won't be planted, consider a cover crop such as oats, rye or vetch. In western Oregon, September and early October are good times to establish cover crops before the weather turns cold and wet.

Keep newly planted seeds evenly moist.

Watch for slugs as the weather cools.

Remove spent summer crops as they finish producing.

Add compost before replanting beds.

Don't rush to remove everything that's still producing.

Start thinking about frost protection for tender crops.

Portland's first frost is typically around mid-November, so there's still plenty of gardening ahead.

Rose City Roots Tip: September isn't the end of the gardening season here. It's the beginning of the fall garden. Get your seeds in now, and you'll be harvesting while everyone else is putting their gardens to bed.