Testing Seeds

I’m in the process of testing some of my vegetable seeds to see if I should try planting them this year. Over time seeds lose their ability to germinate and grow. Some can be kept for surprisingly long by the average vegetable gardener and others konk out after only a year or two. I did some poking around online and found some general ranges for the number of years different kinds of seeds will keep:

Bean 2-4
Beet 3-6
Broccoli 3-5
Brussels sprouts 3-5
Cabbage 3-5
Carrot 2-4
Celeriac 3-5
Cauliflower 4-10
Celery 3-5
Chard 3-5
Chicory 4
Chinese cabbage 3
Collards 5-10
Corn, sweet 2-4
Cucumber 5-10
Eggplant 2-6
Endive 5-7
Fennel 4
Kale 4-5
Kohlrabi 3-5
Leek 1-3
Lettuce 2-6
Muskmelon 5-10
Mustard 4
Okra 2-4
Onion 1-2
Parsley 1-4
Parsnip 1-2
Pea 2-3
Pepper 2-4
Pumpkin 2-7
Radish 3-5
Rutabaga 4
Salsify 1
Spinach 1-5
Squash 2-7
Tomato 4-10
Turnip 4-5
Watermelon 4-5

These numbers were compiled from different sources and depend quite a bit on how the seeds have been stored. For gardeners without high tech storage facilities, cold, dry, dark storage is best.

I haven’t made a habit of testing seeds before this season but a couple of things inspired me to do so. First, two packets of carrot seeds I ordered last season failed to perform. The other seeds I got from the same company did just fine. The four-year-old carrot seeds I picked up from the "share shelf" at the community garden sprouted and grew like champs. Second, as I started doing my garden planning for 2013 I did a seed inventory and noticed I’ve got seeds as much as six years old.

Seed TestingTesting seeds is a simple process. Label a strip of paper towel with a pencil–ink runs–with  the name of the plant. Moisten the towel and scatter the seeds toward one end. Fold it over so the name shows and stack your little bundles in any container that will keep them from drying out. Plastic bags or boxes and glass jars work well. Check them periodically and note on the original seed packet when you tested them if they prove viable. Pitch the seeds that don’t sprout after a reasonable time. If you want to be even more methodical you could count out the seeds and record a percent germination for each variety.

These sprouts show that my ‘Amsterdam’ seasoning celery is still alive and that I can sow some this year with some confidence I won’t be wasting time and garden space on dead seeds.


The biggest surprise so far has been that the fava and scarlet runner beans I’ve had in a jar on the kitchen windowsill for over three years sprouted. That’s within the reasonable window of viability for beans, but they’ve been exposed to direct light, temperature and humidity variations and the horror of seeing their kin cooked and eaten. Once the couple of beans I tested sprouted I couldn’t throw them out so I potted them up instead. Any green growing thing is welcome this time of year.

FavaDo you save seeds from year to year? Have you ever tested them like this? I’m interested to hear about your experience in the comments.