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Harvest, Storage & Post-Harvest TimingRoot Cellar Calendar
A root cellar works because it stays cool and humid with little energy. It needs preparation before harvest and steady attention while it is full.
Key points
- Clean and prepare the cellar before harvest.
- Load crops by need, using your own local frost dates and cellar temperature.
- Use night ventilation to hold temperature and watch humidity.
- Check weekly and use the shortest keepers first.
What does a root cellar do well?
A root cellar holds cool temperatures and high humidity using the earth around it. That suits carrots, beets, parsnips, turnips, cabbage and potatoes. It is less suited to crops that want dry conditions, such as onions, garlic and winter squash, which usually do better elsewhere in the house.
Extension publications from Missouri and Alaska describe how different cellar designs work and what they hold best. Read one for your region before you build or buy.
If you do not have a cellar, a cool basement corner, an unheated room or an insulated outbuilding can do part of the same job, and the same calendar applies to them.
What should you do before harvest?
Clean and air out the cellar. Remove old produce, sweep out soil and debris and fix any leaks or pests getting in. Let it dry and then settle to a cool temperature. Put thermometers at several heights, since the top of the room is warmer than the floor.
Check vents and screens. Good airflow and a way to adjust it are what let you manage temperature and humidity through the season.
Think about pests too. Mice and other animals find a full cellar quickly, so seal gaps, keep food in covered or screened containers and check for signs of chewing during your weekly walk-through.
When do you load the cellar?
Move crops in when the cellar has cooled and the crop is ready. Some crops need a cure first and some are best left in the garden until cold weather arrives. Timing depends on your fall weather, so use your local first frost date and the actual temperature in the cellar.
For example, if your cellar is still warm in early fall, you may want to wait until nights cool and you can open vents overnight to pull the temperature down. Load the crops that tolerate the cool end first.
Do not rush the first load. A cellar that is still warm will start crops sprouting or softening before the cold arrives, and a few extra days of waiting costs less than a bin of spoiled roots.
- Clean, dry, handle gently, sort out damaged roots
- Use clean crates, bins or sand layers as described by extension
- Label by crop and date
- Keep space between containers
How do you manage temperature and humidity?
Open vents at night when it is colder outside and close them when it warms up. Watch for condensation, which is a sign that humid air is meeting cold surfaces. Too little humidity wilts roots, and too much with poor airflow encourages mold.
Check the readings often in the first weeks, since the cellar will be adjusting. After that, a weekly check is usually enough in a stable cellar.
A worked example: if your cellar reads cooler near the floor and warmer near the ceiling, put the crops that like the coldest conditions low and the ones that tolerate a little more warmth high. Your thermometers tell you where those zones are.
Which crops go where?
Group crops by their needs. Roots and cabbage go in the cooler, more humid part. Potatoes need darkness to avoid greening and should be kept away from apples. Strong-smelling crops should be separated from those that take on odors.
If your cellar has a warmer, drier corner, use it for crops that need less humidity. If not, store those crops somewhere else.
How do you check and use stored food?
Inspect stored crops weekly at first and every two weeks later. Remove anything soft or moldy and use damaged items quickly. Eat the least durable crops first, and leave the best keepers for late winter.
If you notice sprouting, shriveling or off smells, check your conditions and adjust. A change in the weather often explains a change in the cellar.
Keep a notebook by the door. Jot the date, the temperature, the humidity and anything you pulled out. Those few lines make it easy to see trends before a problem gets large.
What do you do at the end of the season?
As the cellar empties, clean it out, note how each crop held and write down what you would change. Leave it open to dry and air before closing it for the summer.
These notes become next year's calendar. Over a few years you will know how your cellar behaves and when to load and unload it.
If the cellar worked well, record what you stored and in what amounts so you can plan the garden around it. If it did not, write down the problem while it is fresh, whether it was warmth, dryness, mold or pests.
Sources and further reading
Last reviewed: November 2026. Educational information, ranges only. Confirm timing with your county extension office.