In the News -
March 2008
Seed Viability - How Good Are Your Seeds?
PINE BLUFF, Ark. - A simple test can save gardeners and farmers valuable
replanting time and money, says Dr. Obadiah Njue, University of Arkansas at Pine
Bluff (UAPB) Cooperative Extension Program horticulture specialist. With the
gardening season under way, Dr. Njue recommends testing the viability of seeds
whether they are leftover ones stored from last season, new ones purchased from
a nearby seed store or those ordered from a seed catalog.
A viable seed is one that germinates and produces a new plant. As seeds age,
their potential to germinate, (viability) decreases. Viability depends upon age
and storage conditions. A cool and dry environment is ideal. Generally, newly
purchased seed from seed companies have good viability, but sometimes seed are
not handled or stored properly, says Dr. Njue.
Gardeners or farmers who experienced germination problems with a particular
seed type last year should definitely test that seed for viability. Anyone
unsure as to the age of their seeds or anyone curious should test their seed.
Dr. Njue recommends the following process to test for seed viability.
- Tear off two sheets of a paper towel, and stack them or stack one
napkin on top of another.
- Dampen the paper towels completely (a mister bottle works well).
Towels should be evenly moist, not dripping wet.
- On one moist paper towel, place 20 to 100 seeds (the more seeds,
the greater the accuracy) and carefully place the second paper towel
over the seeds.
- Put the paper towel in a resealable plastic bag. Label the bag with
seed type and date.
- Set the bag in a relatively warm place (70F - 80F).
- Check regularly for germination. Record the number of germinated
seed and determine the percentage rate.
- Mist the paper towels lightly if they begin to dry out.
A 70 percent (70 out of 100) or higher germination rate is considered a good
viability rate, says Dr. Njue. Germination rates of 40 percent to 70 percent
require planting more seeds than usual to get the desired number of plants.
Seeds with a germination rate below 40 percent should be discarded.
The following table gives the average shelf life and germination time of
seeds if stored properly. If seeds take longer than indicated on the table
below, they should be discarded as their viability is questionable, says Dr.
Njue.
| Seed Type |
Storage
(years) |
Germination
Time (days) |
| Beans |
3 |
7 - 14 |
| Broccoli |
5 |
7 - 10 |
| Cabbage |
5 |
10 - 14 |
| Carrots |
3 |
10 - 14 |
| Cauliflower |
5 |
5 - 7 |
| Corn |
2 |
5 - 7 |
| Cucumbers |
5 |
7 - 14 |
| Lettuce |
5 |
4 - 6 |
| Onions |
1 |
10 - 14 |
| Peas |
3 |
7 - 10 |
| Peppers |
2 |
7 - 10 |
| Pumpkins |
4 |
7 - 10 |
| Spinach |
5 |
7 - 21 |
| Squash |
4 |
7 - 10 |
| Tomatoes |
4 |
7 - 14 |
| Watermelons |
4 |
5 - 7 |
Dr. Njue reminds those raising seedlings that time is running out for cool
season crops that include collards, kale, broccoli and cabbage. Many of these
require six to eight weeks before the last frost for transplants to get to
optimum size.
March 7, 2008
By: Carol Sanders
Writer/editor
UAPB School of Agriculture
Fisheries and Human Sciences
(870) 575-7238
sanders_c@uapb.edu
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