I originally posted this on the lawn care forum a year ago. I didn't get around to posting it here, but someone was looking for recently, so here is the belated experiment posting.

My bluegrass germination experiment (long-sorry)

Posted by quip 5 WI (My Page) on Wed, Sep 1, 04 at 11:11

I recently posted a question about people's experience priming or pregerminating seed. I didn't find a lot of homeowner level (vs golf course, sports field). So I did a little experiment and was asked to post results. Here are the early results.

Situation: Seeding a sloping shallow drainage swale (newly installed), loam soil, pH 7.3, high nutrient levels per recent test. Seedbed soil loosened with hand tools and raked. NK Kentucky bluegrass seed was used. Lawn located in SE Wisconsin, highs temps 68-80. Rain or watered 2-3 times per day as needed.

For some test plots, I mixed seed with used coffee grounds from local coffeehouses--damp, not wet. I used 2# seed to 3.5 gal grounds (proportions were randomly selected) in covered 5 gal bucket. Seed/grounds were mixed initially and then inspected and mixed once a day. First plots were seeded by hand after 5 days of pre-treatment, lightly raked and lightly mulched with more coffee grounds.

At the same time as pre-treated seed was sown, "control plots" were hand sown with untreated seed straight from the same box. Lightly raked and lightly mulched with coffee grounds in same manner as pretreated plots (in case the grass seed was responding to coffee in some way).

Pretreated seed plots (5 days in coffee grounds): First germination seen 5 days after planting. Brisk germination by 7-8 days after planting. Now, at 12 days after planting (17 days including pre-treatment time), I have 90+% coverage with small bluegrass seedlings averaging 1 inch tall.

Control seed plots: First germination seen at 7 days, with gradual and continuing germination to date (12 days). As of day 12, I have about 35% coverage with seedlings ranging from just visable to 1 inch (average about 5/8 inch). Hopefully these plots will continue to fill in over time, as germination is continuing.

I also did pretreated plots with longer pretreatment times (8-12 days pretreatment). These are still early, but so far I have seen no great difference (good or bad) from behavior of 5d treated seed.

This is, of course, very limited data, but here's how I feel about my early results:

1. Ease--The pre-treatment was easy for me to do on my small scale, and seed was easier to care for in the pre-treatment bucket than on the lawn. Minimal time and water used during pre-treatment. Seed/coffee ground mix was easier to spread by hand evenly than plain seed was (could see where I'd been and control mix easily). But I didn't need to try a spreader, so I dont know if it would have worked or not. A really large scale seeding might need a different treatment protocol to keep it easy (I did see a pre-germintion protocol from Milorganite on the web after the fact :-(. Don't have the url- you could google it.)

2. Germination rate-The pretreated seed germinated faster and more evenly than the untreated seed as measured from date sown. Allowing for the days the seed spent in the pre-treatment bucket, the improvement may be unimpressive (that is comparing 5 d pre-treated at 7 d post sowing to untreated at 12 days post sowing). But it is still early.

3. Would I pre-treat bluegrass seed again? More time may change my mind, but here's how I feel today. If I had the seed, but the seed bed was not ready (as in my current case), I would not hesitate to pre-treat again. If I were going away and could not care for the seedbed, I'd pretreat and ask a friend to mix daily in my absence. If the area were hard to water, I'd pre-treat to save several days of watering the bed. If the time was right for seeding, but the weather conditions were predicted to be adverse for a few days, I'd pre-treat. On a slope (like mine), I'd pretreat to reduce wash out. If I wanted mostly bluegrass, I might pretreat only the bluegrass, and not the other quicker seed types to give the blue a head start.

But, if I had the perfect, level, easy-to-care-for seedbed all set with favorable weather forecasted, heck, I'd probably just seed it straight. If I were using a quicker germinating seed (like rye), I'd probably just seed straight.