Natural Areas Maintenance from the JFNew Nursery Newsletter, 2009
As the year winds down, fall is a great time to prepare new areas for a dormant or “frost” seeding. Many people associate fall plantings with just cool-season grasses, but many wildflower species do well if planted in the fall. The ideal planting time
is from November through March, when soil temperatures are at fifty degrees or below. Cool soil temps will keep the seed dormant in the seed bed, while natural freezing and thawing processes will help work the seed into the proper depth for germination (usually less than a quarter of an inch).
Cold, saturated ground will also stratify the seeds, allowing them to break their hard seed coats, and increase germination in the spring.
If planting on a newly graded site, the seed bed should be smooth and relatively free of debris, such as rocks and stumps. If bringing in additional soils, make sure that the soil is weed-free. Seed can be broadcasted or installed using a no-till seed drill. After broadcasting the seed, the area should be rolled with a light turf roller to increase seed-to-soil contact. Cover the area with an erosion-control blanket suitable to the slope for protection against erosion and herbivory during the winter months.
Seeding into an existing native planting or moved stubble can be a little trickier. The best application method is to use a no-till seed drill that can cut through the existing thatch and deposit the seed at the correct depth. If a drill application is not possible, seed can be broadcast into existing growth, but the area should have been mown in preparation, and the thatch removed to increase seed contact with the soil. Covering with a blanket is not necessary, as the existing vegetation will help prevent erosion and hold the seed in place until the spring.
Garlic mustard evolves
We’ve known for a while that garlic mustard exudes a toxin from its roots that kills mycorrhizal fungi in the soil. While garlic mustard does well on its own, finding nutrients and water without the assistance of the symbiotic relationship with soil fungi, that is not true of the native plants that might grow in the areas that garlic mustard has infested. Even tree seedlings have trouble surviving in the midst of a plague of garlic mustard. Now research has shown that lower levels of fungicidal compounds are produced by a thirty-year-old stand of garlic mustard than by a twenty-year-old stand. It was found that older populations of garlic mustard – though still problematic – posed less of a threat to native plants than the newer stands.
While this study focused on only one alien plant, the results indicate that some invasive plants evolve in ways that may make them more manageable over time. This suggests that conservation efforts might be more effective if they are focused on the most recently invaded areas, which – in the case of garlic mustard, at least – is probably where the most damage occurs.
Kudzu
Then there is the invasive plant that earns names like “the plant that ate the south,” and shows no sign of modifying its march across the countryside. Latest reports indicate that it has reached Summit County, Ohio, and Leamington, Ontario, Canada, pretty much directly across Lake Erie from Summit County, Ohio.
It is likely that we’ll be seeing more kudzu (Pueraria lobata) in areas that were previously kept safe by long cold spells during winter. For more information on identification go to www.invasive.org.
Plant some swamp milkweed
Asclepias incarnata L., swamp milkweed, is not blooming now, but it will soon be time to plant some. This was my very first native plant, but I didn’t know it. I bought something called “butterfly weed” from a garden store. It was not butterfly milkweed, (Asclepias tuberosa L.), but I was not misled, as I got lots of monarchs, including eggs and caterpillars – (I had never seen a pupa) – and great spangled fritillaries in my city garden. I also first saw how many different sizes of bees there were in my garden.
Swamp milkweed grows three to six-feet tall, and my plug grew bigger around each year, but did not spread aggressively. It looks good in the early winter, too. When I moved to my woodland garden I couldn’t live without it, and even with partial sun, smaller plants still bring in the butterflies. This is a plant for many gardens.
Common name comes from its preference for a wetland habitat. Strictly speaking, a misnomer, as swamps are by definition wooded wetlands, and this plant thrives in the sun. Pods dry beautifully and are often used in arrangements. Flowers used fresh in arrangements, but ends must be seared to prevent wilting. One of the few ornamentals that thrives in mucky clay soils. Soil neutral to slightly acid – will tolerate heavy clay. Will thrive in average garden soil, so long as it doesn’t dry out completely, especially in spring. Quite drought tolerant.