Spring fever – the malaise characterized by a painful longing for milder weather, leafy plants and flowers – is gone, thanks to the seasonal sensory pleasures we are now seeing, feeling, smelling and even tasting.
It’s been replaced by spring frenzy, the prepping, planting and panting that goes with a gardening season in full swing.
Ideally, one essential chore, soil preparation, should have begun last fall, but there’s still time to take some steps to have healthier soil and plants.
Not prepping the soil is like building a house without a proper foundation, said Chris Cosby, senior manager of gardens at the Memphis Botanic Garden.
But that doesn’t mean renting heavy equipment to churn up the dirt.
Never till with rotary tiller, Cosby said at a seminar on Gardening on a Shoestring put on by the Memphis Area Master Gardeners.
The best way to improve soil is to observe how nature creates fertile places, he said.
How many bags of leaves do you find in a forest? he asked. There’s no leaf removal in the forest. Its soil depends on annual leaf cover.
Decaying leaves, grasses and other organic materials in forests and grasslands contribute to development of a web of vital fungi and bacteria that 90 percent of plants need to thrive.
To grow a good garden, you don’t need to learn soil science, Cosby said. Just add an inch of compost to the top of the soil after each harvest.
In their book, Teaming with Microbes: A Gardener’s Guide to the Soil Food Web (Timber Press), Jeff Lowenfels and Wayne Lewis report:
A teaspoon of good garden soil, as measured by microbial geneticists, contains a billion invisible bacteria, several yards of invisible fungal filaments, several thousand protozoa and a few dozen nematodes.
It’s what’s called living soil.
Each cubic foot of living, healthy soil is also home to about 50 earthworms, which shred organic materials and deposit their nutrient-dense castings.
This living web of interconnected organisms is destroyed when soil is tilled. Salt-based synthetic fertilizers such as those with three numbers – like 13-13-13 – Miracle Gro and others also kill off portions of it.
If you are spraying pesticides and using fertilizers like Miracle Gro, you are dissuading the fungi, Cosby said.
Lowenfels and Lewis write: Rototilling breaks up fungal hyphae (filaments), decimates worms and rips and crushes arthropods. It destroys soil structure and eventually saps soil of necessary air.
So what’s the best way of dealing with the rock-hard clay many gardeners struggle with, especially those whose property was scraped and leveled for new construction?
With gray clay, raised beds and patience are your friends, Cosby said.
Instead of engaging in backbreaking work to change the texture of all your compacted soil, it’s easier and more beneficial to create a comfy place for plants by gently loosening the soil with a spading fork and then piling 6 to 8 inches of homemade soil mixes on top of the hard surface.
For shady woodland areas, Cosby uses a mix of one part leaf compost, one part finely shredded pine bark sold as soil conditioner and one part coarse builders’ sand.
Do not use peat moss, he cautions, because it doesn’t have enough bulk to last through hot summers and is not a renewable resource.
Washed river sand is not recommended because it is fine enough to mix with the other components to form a concrete-like substance.
For perennial beds that get more sun and are home to plants that like neutral or slightly alkaline conditions, Cosby substitutes cotton-burr compost for the leaf compost.
Most people can’t make enough compost from their yard waste to meet all their needs without piling up massive amounts, Cosby said, adding that finished compost has a volume of about one-tenth the original pile.
In a year or two, the amendments will settle into the level and look of other beds.
That decomposition is speeded by the work of earthworms, which open air passages as they travel through the soil to reach the leaf litter and compost they find so yummy.
Their passages also increase the soil’s capacity to hold water and its ability to drain it away.
When it comes to installing plants in newly established beds, Cosby doesn’t like to take a chance on the soil containing enough of the mycorrhizal fungi.
(Mycorrhizal comes from the Greek words mykes, meaning fungus, and rhiza, meaning root.)
He and other employees at the Botanic Garden add a teaspoon or two of commercially produced fungi to the planting holes and also to pots of new plants.
We inoculate all of our planting holes with mycorrhizal fungi, he said. And if you buy plants from us, you will be inoculating the soil because we use it in the potting soil of everything we grow.
The fungi aid in a plant’s ability to take in water and nutrients by causing roots to grow larger and deeper. The plant experiences faster growth and improved ability to handle the stress of heat and drought.
They can also reduce the need for fertilizer and irrigation, increase resistance to diseases and enhance transplant establishment and plant health and vigor.
In existing gardens, products containing the fungi can be sprinkled on top of the soil before adding a layer of compost and mulch.
They stimulate new feeder roots that grow near the top of the soil, said Cosby, who knows how well good soil preparation paired with giving individual plants a boost with mycorrhizal fungi works.
Plants in three new gardens at the Botanic Garden – the children’s, herb and wildlife gardens – withstood the stresses of being installed during hot, dry summer months.
The next year, they showed vigor and size not usually seen until the third year after planting.
Online sources for it include Fungi Perfecti at fungi.com; Mycorrhizal Products at mycorrhizalproducts.com and Peaceful Valley Farm Supply at groworganic.com.