Gardening Column

Support local journalism by subscribing today! Click Here to see our current offers.

Storing carrots and potatoes

Carrots do store well in the ground except for two issues, field mice (voles) and carrot root maggot. If you don’t have mice (or rats) and have seen no sign of carrot rust fly maggot damage (surface tunneling on roots that turns dark) then it is ok to

leave them there until late January. After that, you need to bring them in to avoid them turning bitter in response renewed growth that leads ultimately to flowering. Also never store potatoes and carrots with either apples or onions. The ethylene gas given off by apples or onions will cause the carrots to get bitter and the potatoes to sprout.

Squash and cucumber comments

Most gardeners have lots of winter squash. Varieties such as Acorn, Buttercup, Butternut, and Hubbard (to name a few) will store well for at least four months. Harvesting the oldest squash can start now. Clip the squash from the vine leaving a couple inches of stem except with Hubbard squash which store best with the stems removed.

Wash squash with a mix of one part bleach to nine parts water, dry it off, and leave it in a room that is very dry for about two weeks. This will form a hard shell on the squash that will make it more resistant to storage diseases. Then put it in a dry garage or basement for long-term storage, Check the squash periodically to remove those showing any signs of rot. Keep the mice away.

You can hold off harvesting the remaining squash while we have nice weather. But if we head toward an extended rainy cycle, harvest the squash before the rain starts so they won’t rot on the vine. Temperatures consistently below 50 degrees also reduce storage time. Freezing temperatures injure squash and cause decay.

The towns along the Columbia from Scappoose to Clatskanie usually get the first fall frost around the last week in October but it can come sooner. Higher elevations may frost as early as the end of September. Finally, if the squash vines are consumed with powdery mildew, the squash aren’t going to grow well anyway, so get them out of the garden and into storage.

Powdery mildew is a fungus favored by warm, humid weather and early morning dew. I get a lot of calls about powdery mildew on squash and cucumbers. What gardeners discovered this year is that some squash got it and other varieties didn’t.

Varieties have been bred to be mildew resistant but are not always sought out by gardeners or growers of transplants. Next year, examine the seed catalogs for versions of your favorite squash and cucumbers that have powdery mildew resistance. Sulfur dusts and sprays can be used effectively if applied before the disease is really rolling. Some recent research indicated that milk sprays (1 part milk to 9 parts water) may help with the disease, again with a spray program started before the disease shows up, usually near the end of June at the latest. Another squash disease, angular leaf spot, can also be somewhat managed with resistant varieties.

I have had a number of calls about bitter cucumbers. There are several factors that influence whether a cucumber will be bitter. First is breeding. The pickling lines are generally bitterer if eaten fresh than the slicing varieties. The bitter flavor disappears when they are pickled.

Stress accounts for the bulk of bitter complaints. For a cucumber, stress can be low temperatures, moisture stress when it gets really hot, or an attack of powdery mildew. Cucumbers from the same plant can be bitter one week and ones that ripen the following week or so may be fine. The bitter flavor is concentrated on the stem end and in or just under the peel.

Plant garlic next month

If you like garlic, get out there and plant some late this month or in October. Find a sunny, well-drained space, lime it with about 10#s per 100 square feet, add some compost and fertilizer and you are ready to plant. Go to a Farmer’s Market soon (they are about to end) and buy several varieties of garlic. Get the names and label them in bags. Separate out the cloves from the bulbs and plant the biggest cloves from each variety.

Mark your rows so you know what did well. Eat the cloves you didn’t plant. Space the rows about 12” apart and the garlic about 3” apart within the row and the cloves about 2” below the soil surface. Cover with one inch or so of compost or some other organic matter to keep rain from crusting the soil. Sit back and wait. You may not see tops until January but rest assured that the plants are doing just fine.

Weed often. Fertilize after February and again in late April. Water as needed. If it is a “hard neck” garlic, pull the flowering shoots off when they show up in May or early June. Harvest in July. That’s it.

Pressure Gauge Testing

Free at the Extension office in St. Helens. Contact for questions and requests for accessibility-related accommodations: by phone (leave a message for Jenny Rudolph) 503 397-3462 or by email at

COVID restrictions are still in place at our office which is located at 505 N. Columbia River Highway, St. Helens, OR 97051.

Free newsletter

The Oregon State University Extension office in Columbia County publishes a monthly newsletter on gardening and farming topics (called County Living) written/edited by yours truly. All you need to do is ask for it and it will be mailed or emailed to you. Call 503 397-3462 to be put on the list. Alternatively, you can find it on the web at and click on newsletters.

Many Extension publications available online

Are you putting up salsa, saving seeds, or thinking about planting grapes? OSU has a large number of its publications available for free download. Just go to Click on publications and start exploring.

The Extension Service offers its programs and materials equally to all people.

Contact information for the Extension office

  • Oregon State University Extension Service – Columbia County
  • 505 N. Columbia River Highway St. Helens, OR 97051
  • 503 397-3462
  • Email:

Online Poll

(0) comments

Welcome to the discussion.

1. Be Civil. No bullying, name calling, or insults.
2. Keep it Clean and Be Nice. Please avoid obscene, vulgar, lewd, racist or sexually-oriented language.
3. Don't Threaten. Threats of harming another person will not be tolerated.
4. Be Truthful. Don't knowingly lie about anyone or anything.
5. Be Proactive. Let us know of abusive posts. Multiple reports will take a comment offline.
6. Stay On Topic. Any comment that is not related to the original post will be deleted.
7. Abuse of these rules will result in the thread being disabled, comments denied, and/or user blocked.