Ralph Purkhiser, Purdue University Master Gardener
Spring planting time is well underway, but it is important to wait until the soil is ready for your plants. Several factors affect the planting time for different plants.
Temperature is a major factor in deciding when to plant. While trees, shrubs and perennials hardy to this zone will tolerate cool soils, tender plants, including vegetable starts and annual flowers, need for the soil to be warmer to thrive. Planted when the soil is too cool, the plants will, at best, sit there and not develop until the soil warms. On the other hand, some plants will develop problems, including root rot. The same is true of seeds. Some need warmth for germination, and planted too soon may result in rotting seeds. It is best to wait until the soil is warm enough for healthy growth.
Moisture is also needed for plant development and seed germination, but April showers often bring too much moisture. It is best to stay out of the garden when the soil is too wet. Make a ball of soil and drop it from about five feet off the ground. If the ball falls apart, it is dry enough to work the soil. If the ball remains intact, the soil is too wet. Walking on the wet soil will cause compaction that may plague you for a long time.
Soils are not equal. Clay soils tend to hold moisture longer, but are also more subject to compaction. Sandy soil will have good drainage, but may not hold enough moisture to promote good plant growth. It takes organic matter to improve the tilth of the soil. The easiest way to add organic matter is with compost. You may purchase compost or make your own. As I noted in the planting instructions last week, the best way to add compost is to put it on top of the soil surface and let the earthworms and insects in the soil incorporate it into the soil.
In the past, it was recommended to till compost into the soil, but tilling may be counter-productive. The soil contains many living organisms, and tilling may kill those organisms. Soil scientists have learned that certain fungi form a symbiotic relationship with the roots of plants. These are known as mycorrhizae. I will not pretend to know how mycorrhizae work, but they enable plant roots to take up minerals, and in turn, the fungi are nourished by products produced by the plants. Both organisms benefit from this arrangement.
This is one of the reasons that many farmers have converted to no-till operations, using a drill planter to plant seed with minimal disturbance to the surrounding soil. This practice has the bonus effect of reducing erosion of the soil. The easiest way to incorporate this practice in your vegetable patch or flower garden is to garden in raised beds. Not only are you able to control the soil used in the beds, but you may plant with minimal disturbance.
Friday, April 26 is Arbor Day in Indiana. It is a good time to plant a tree. If you do not have room in your landscape for a new tree, consider donating a tree to be planted in a park or other public space, or donate a tree to an area where wild fires have destroyed the forests. Planting a tree demonstrated your hope for the future.
I want to thank everyone who came and purchased plants last Saturday at the Hoosier Hillsides Master Gardeners’ plant sale in Orleans. It was a very successful sale, and I was able to meet readers from Orange, Crawford, Martin and Lawrence Counties. Enjoy your new plants.