COLUMN: Purdue Extension: Ready, set, plant!

There are a few practices that gardeners and farmers alike depend upon to get a plant to grow in the spring.

Soil temperature

Clay soils take time to warm and provide an environment that is conducive for good germination of seed or start of transplant development. Darker soil, typically with more organic matter, tends to warm up faster than a brown soil type. Soil temperature needs to be in the range of 50 degrees for germination. Deeper planting will make a lesser temperature, and more crop residue will cool soil down. Anyone planting seeds must monitor soil temperature and be mindful of soil type, depth of seed placement and residue cover. Potatoes can be planted now but plant them two to three inches deep, otherwise sprouting may be subdued by a cooler soil temperature.

Planting later in May typically ensures warmer soil temperatures will follow. April planting can be tricky and seed placement an inch too deep can be problematic. Also, small seeds require less soil depth at planting. Don’t bury your mustard seeds!

Soil contact

We call this seed-to-soil contact with respect to planting seeds, be they lawn grass, corn or lettuce. The seed needs coverage of soil to have a moist environment and to not dry out. We typically get enough rain in April to not have a dry seedbed issue. But never say never. I had soybean seed one dry spring that took two extra weeks to germinate because of a dry seed bed. Getting seed covered with soil is important: lawn grass only needs a spritz of soil covering the seed to do well. Again, follow planting depth recommendations and don’t plant too deep.

Light

Trick question! Seeds DO NOT require light to germinate. What light reaches a seed of corn planted two inches deep? Seeds need oxygen and moisture. Get that seed covered. Light is only a necessity when photosynthesis starts.

Good seed

Germination of seeds is not a problem with stored seeds that are dry and have not been compromised with moisture. I am never afraid to plant

seed from last year, if it has been stored properly. The University of Illinois has a fascinating study going back decades where seeds were stored and each year some were planted and germination recorded.

Early season diagnostics

Each planting failure or problem sets up a crime scene investigation. “Why did my seed not grow?” could be due to a variety of causal factors like insects, fungal disease or soil conditions. Like any crime scene, the earlier you collect evidence, the better your chances to figure out what went wrong. Standing in foot tall corn trying to determine why there are skips in the row is often able to yield enough clues. Monitor your garden or crop field weekly and give me a call at 812-829-5020 or email luzar@purdue.edu if you have questions. Happy planting!