What to Do With a Container Garden in Fall

By the end of this page your summer pots will be cleared, the healthy ones replanted with cold-hardy greens or garlic, and the rest emptied and put away for winter. Expect an afternoon of work.

The one thing to know first is that frost sets the schedule. A light frost is 32°F, which kills tomatoes and peppers. A hard freeze is 28°F, which kills hardier crops like spinach and kale, according to The Old Farmer's Almanac.

1. Pull the summer plants. Do it after the first light frost blackens the foliage, or sooner if they have gone weak, bitter and stopped producing, which is the end point the University of Maryland Extension describes. You should be left with a pot of bare mix.

2. Sort what you pulled. Healthy stems and leaves go in the compost. Diseased plants go to a yard-waste service, not a home pile, per University of Illinois Extension, because leftover material can carry disease and insects into next year.

3. Judge the mix. If a pot had root disease this season, throw that mix out. Pathogens persist in it, and UMD says not to save it.

4. Pick out the debris. Remove plant tags, dead leaves and old roots from any mix you keep. What remains should be loose and free of plant matter.

5. Blend the old mix with new. UMD's ratio is 50:50 old mix to fresh mix or compost, worked together with a hand cultivator. The result should look darker and crumblier than the old mix alone.

6. Add slow-release granular fertilizer. Mix it through before planting.

7. Plant the fall crops. Kale, spinach and radishes survive below 28°F, and lettuce tolerates 28 to 32°F, per the Almanac. Garlic also works if the pot is deep; the timing and depth are covered in planting garlic this month. You should see seeds sown or transplants settled and watered.

8. Empty the pots you are not replanting. Store the cleaned mix in cans, tubs or heavy-duty bags until spring.

9. Clean the empty pots. The extension sources used here do not give a cleaning solution or ratio, so check your state extension service's recommendation before you mix one.

10. Bring terracotta inside before a freeze. Unglazed terra cotta and ceramic absorb winter moisture and crack as it freezes and thaws, UMD notes, and Proven Winners puts glazed ceramic and porcelain in the same risk group. Plastic, metal, wood and composite hold up better outdoors.

11. Write down what grew well. Illinois Extension recommends noting which varieties performed and which pots they were in, for spring planning.

Your pots are now either growing cold-season food or stored with mix ready for spring. If you are adding pots for fall greens or garlic, size them before you buy.