Friday, April 30, 2010

Coir vs Peat in a Sub-Irrigated Planter (SIP): Three Weeks In

Planted on April 1, 2010. Photo taken April 22.

At left, collards in 70%coir/30% perlite. On the right, 70%peat/30%perlite.

We're wondering if the coir mixture is wicking at all. After a heavy rain, the coir SIP perked up, but the plants in the peat mixture continue to outpace it.

Stay tuned for further updates...
Bruce is testing other blends of coir+peat. For now, I'm extending our peat/perlite potting mix (on its third year) with a percentage of coir for current plantings...but not going the all-coir route.

1 comment:

Bruce said...

The experiment isn't looking good over here either.

On April 12th, I planted four SIPs; each with the same sampling of greens--tatsoi, bok choy, chard, rapa.

#1 - 30% old mix (coir/earthworm castings, peat) from my potato box experiment, 50% old potting mix, 20% perlite.

#2 - 70% old BAACTO potting mix, 30% added perlite

#3 - 40% old BAACTO potting mix, 40% coir, 20% perlite.

#4 - 70% coir, 30% perlite.

All got the same amount of 3-3-3 organic fertilizer.

SIP #2 looks great, closely followed by #3. #1 looks like it's struggling, not thriving. #4, while not as bad looking as the plant in your photo, is fugly.

The strange thing is that all the tomato, eggplant, and pepper seedlings I've started--not to mention all the cold weather seedlings--in the 70/30 coir/perlite mix are still going strong.