© 1999 Streamline Publications

Even with the best science and technology, seed germination and survival is a crap-shoot. Ol' Mother Nature can be a capricious master and resist our earnest attempts to produce crops, revegetate disturbed sites, grow ornamentals, or manage turf. No matter how much we like neat numbers that fit precisely into our calculations, we are often thwarted by the old gal.

The foregoing preamble is by way of helping us deal with the fact that seed doesnt always result in plants. The old farmers knew this from experience and clung to the adage:

One for the worm,
one for the crow,
one to rot, and
one to grow.

Study What Happens

Still, we'd like to have a better idea of what it will take to do the job—how to adequately budget for worms and crows and rot.

In 1994 the U.S. Department of Agriculture reported on a Soil Conservation Service, Lockeford Plant Materials Center study. The study was of seeding rates and resultant germination of 22 selected grass species including clovers, bromes, fescues and others. The inquiry—conducted for Caltrans—involved planting each specie separately in boxes 2 feet by 6 feet by 7 inches deep that were elevated to a 2:1 slope. The plant stands were evaluated after 30, then after 60 days.

Seeding rates were based on at least 80 percent viable (pure live) seed per pound and seeds were planted at the rate per square foot of soil.

The Results

After 30 days and 60 days the number of plants per square foot were recorded. The results varied widely among species, as is evident in the table of examples, above. In some cases there were fewer plants after 60 days than there were after 30 days.

examples of study results
species	seeds sq/ft	30 days plants sq/ft	60 days plants sq/ft
Subclover	30	5	14
Regreen	11	6	9
Annual Ryegrass	115	39	73
Purple Stipa	54	1	8
Pine Bluegrass	689	132	120
Idaho Fescue	155	44	40

Among the 22 species in the study the seed-to-plant ratio after sixty days ranged from
2 to 94 percent.

The study comes with the caveat that the information may be used with due consideration being given to the seeding rate, soil characteristics, and the methods of the study. Pretty clear recognition that seeding rates bear little overall relationship to the number of plants one can expect to become established, even under relatively controlled conditions.

The study report bears a note that: Initially, rodents severely grazed the clovers and subclovers, clear recognition of the perils plants in the wild face. That point alone is instructive and illustrates the thesis of this article: You cannot count on the numbers alone.

What To Do

When considering a seed purchase—whether for commercial or government projects, the available numbers can be judged and refined by those experienced in the vagaries of seed and nature.

We suggest contacting the consultants at Albright Seed Company.

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