Composting Leaves

Keep Your Leaves

By Amy McDowell

Asters, mums, and plump orange pumpkins are adorning our porches and perching on our steps.  There are corn stalks, straw bales, and gourds – evidence of a generous fall harvest.  It’s beginning to look a lot like autumn – everywhere you go.

This is a great time of year to begin that compost pile you’ve been thinking about.  Composting is simple, and it keeps valuable resources on your lot that you can never replace, no matter how much money you spend.

Healthy soil is loaded with organic matter – that is, decaying plant debris – and all kinds of microscopic organisms. One gram of healthy soil will have 37 billion bacteria and 4 million fungi, plus larger organisms like protozoa, paramesei, and nematodes. Healthy soil means healthy plants, whether they are flowers, shrubs, trees, or turf.

Composting can be as simple as raking your fall leaves into a pile and tossing a few shovels full of soil on top. The leaves will break down more quickly if you shred them first. There are several styles of inexpensive leaf shredders on the market, or you can shred the leaves by running over them with your bagging mower. Shredding the leaves is not necessary, but it is helpful and speeds up the composting process.

If you are wondering where to get the extra soil, consider digging a shallow pit for your leaves and leaving the excess soil around the edges to sprinkle over the top.

You can always till leaves directly into your garden or spread shredded leaves across the surface if you don’t want to make a compost pile. Whatever your method, the key is to keep your leaves, grass clippings, and all of your yard waste except sticks and branches.

Why is your yard waste such a valuable resource for your yard?  In the soil, bacteria and fungi break down plant debris into smaller and smaller pieces for microbes to feed on.  With no plant debris, there is no food source. The soil is unhealthy and barren. In the typical urban environment, the soil is starving because there is no organic matter. Chemical fertilizers are a temporary fix, and they cannot replace precious organic matter.

If you live in an area where the soil has been disturbed by new construction, rest assured that the soil can recover, but it may take decades. The more organic matter you can add to the soil, the more quickly the soil organisms can heal the damage.

As the trees are beginning to shed their leaves, now is a wonderful time to begin composting and recycling your yard’s priceless resources.

Amy McDowell is an Iowa Certified Nursery Professional. She has an associate’s degree in commercial horticulture and has worked in the field for ten years. She lives and gardens in Polk County. 

Fall Color

Raging Red and Flaming Orange

Bold fall colors for your garden

By Amy McDowell

Iowa is blazing with spectacular fall color. You still have time to plant some color in your garden this year. Take a trip to your local garden center and take a look at the vibrant rainbow of warm colors available in trees and shrubs.

Some of the most glorious trees right now are the red and sugar maples decked out in red and orange, and the white and green ashes wearing fall purple and golden yellow hues. Red maples (Acer rubrum) mature to about 40 to 60 feet tall with a rounded canopy. Sugar maples (Acer saccharum) reach 60 to 75 feet tall and tend to be taller than they are broad. Red and sugar maples turn to stunning reds and oranges in the fall. White ash trees (Fraxinus americana) will generally color to royal purple in the fall and green ash (Fraxinus pennsylvanica) will turn vibrant golden yellow. Depending on the variety, ash trees range from 40 to 70 feet tall.

At the garden center, you will find named varieties of maple and ash trees. Named varieties are essentially clones sharing the same genes. The advantage to a clone is that you can be guaranteed genetic traits such as spectacular fall color. Trees grown from seed are genetically diverse and fall color will vary from one plant to another.

If you are thinking about planting shrubs rather than trees, take a look at the intense colors of sumac, burning bush, fothergilla, viburnum, and witch hazel. Sumac (Rhus typhina) is the brilliant red you see along roadsides right now. It is a suckering shrub, so it forms a loose mound about 15 feet tall and about as wide as you will allow it to spread. Burning bush (Euonymus alatus) will stay in bounds at about ten feet high and wide. It is often used as a hedge, and can be kept to a more compact height if you prune it. Fothergilla (F. gardenii) will mature to around four feet and colors to a fiery red-orange-yellow combination in the fall. Viburnums (V. species) are Iowa natives, so they are tough and resilient. To choose a viburnum with great fall color, buy them right now. They turn shades of red and orange, but some species are bold while others are bland. Witch hazel (Hamamelis vernalis) is another red shrub you may see on roadsides right now. It will grow to about eight feet tall and ten feet wide.

Finally, there is the fierce red maple that is too short to be a shade tree, but pretty tall to be a shrub. It is the amur maple. You will see drifts of these along Iowa’s roadways that have been planted by the Department of Transportation. The stunning amur maples (Acer ginnala) often have a multi-stem trunk and grow to about 18 feet tall.

Amy McDowell is an Iowa Certified Nursery Professional. She has an associate’s degree in commercial horticulture and has worked in the field for ten years. She lives and gardens in Polk County. 

Fall Spectacular - Ornamental Grasses

Ornamental grasses for the masses

By Amy McDowell

Rippling gently in the breeze and shimmering in the sunshine, ornamental grasses enliven landscapes in late summer and fall. Grasses come in every size, shape and color, and the plethora of choices may overwhelm browsing shoppers at the garden center.

If you’ve got room in the garden for just a couple of grasses, plant a feather reed grass (Calamagrostis ‘Karl Foerster’) for its striking upright growth and compliment it with the rounded growth of a fountain grass (Pennisetum alopecuroides ‘Hameln’). Karl Foerster feather reed grass grows five feet tall and has dark burgundy seed heads in the summer that fade to beige in the fall. The mounded ‘Hameln’ fountain grass grows two feet tall and has pinkish-brown foxtail-like seed heads.

Regardless how much space you have in the garden, ornamental grasses soon get to be like so many new garden adventures—addictive. Soon you’ll want to experiment with the broad palette of different colors.

For white variegation, consider ribbon grass (Phalaris arundinacea), which tops out around two and a half feet. Striped feather reed grass (Calamagrostis x acutiflora ‘Overdam’) is roughly the same height with burgundy seed heads in the summer like ‘Karl Foerster’. Miscanthus sinensis ‘Variegatus’ has creamy white variegation and a rounded four-foot grass.

For yellow variegation, plant Alopecurus pratensis ‘Aureovariegatus’ or golden hakone grass (Hakonenchloa macra ‘Alboaurea’). Alopecurus grows upright to about one foot and has bright yellow variegation in the spring and red-brown foxtails. Golden hakone grass needs some shade, where the floppy golden grass looks terrific with blue hostas. It grows about 18 inches tall.

Everyone who grows annual purple fountain grass wishes it were a perennial, and the way plant hybridizers work, it won’t be long before we see it. In the meantime, the best red grass that will survive our winters is Japanese blood grass (Imperata cylindrica ‘Rubra’). It isn’t as striking as purple fountain grass, but its green leaves are streaked with blood red edges and tips.

Finally, ornamental grasses can add crisp blues to the garden. Blue fescues are the best known, but they require well-drained soil in order to survive our winters. Grasses are tough perennials and killing a blue fescue with heavy soil is aggravating. Panicum virgatum ‘Heavy Metal’ is a sharp blue-gray grass that grows to three feet. It has arching leaves and airy panicles of burgundy seed heads.

Don’t be afraid to dabble with ornamental grasses. Betcha can’t plant just one.

Amy McDowell is an Iowa Certified Nursery Professional. She has a degree in horticulture and has worked in the field for ten years. She lives and gardens in Polk County, Iowa, United States.