SHR-News

Gardener’s Corner with Director of Horticulture Eric Kimbrel

Much of this season at the Reserve has been spent inside enhancing our digital plant database in preparation for it to be shared with the public, as well as making plans for the coming growing season. On warmer days, we have been able to get outside for some much-needed landscape maintenance including cleanup after winter storm Diego swept through. Several top-heavy rhododendrons were uprooted and toppled over from harsh winds and the added weight of ice and snow during the storm. We have replanted, staked and covered them with horse manure for extra protection while they become reestablished. We also top-dressed beds, shrubs and small trees that had been recently planted. The Wildflower Labyrinth is one exception with regards to manure because excess nitrogen will cause these plants to become leggy and fall over.

In preparation for the completion of our new Nursery Complex trail, we transplanted several cinnamon ferns from the path to nearby locations a few feet away. Our water mitigation efforts continue as we have added oak and maple logs—LWDs (large woody debris)—to woodland areas along topographic lines where elevation changes. This is the first stage of a multi-step process to create bio-swales that will help prevent erosion. Later we will revisit those logs to partially bury them in the soil, and then dig out an adjacent area uphill and refill it with small woody debris like wood chips. This will hold the water in the basin and allow it to slowly seep into the ground rather than quickly run off. The woody debris will also gradually break down into a rich organic matter and provide added nutrients to the surrounding plants and soil.

Inside, we have been laying the groundwork for additions to the gardens. Seed stratification is a naturally occurring process of long periods of cold temperatures breaking seed dormancy and beginning germination. Natural forces throughout the seasons deteriorate the seed’s external coating, allowing water and light to reach the embryo. Horticulturalists mimic those natural forces indoors for propagation. We place the seeds in moist mediums like sand, peat moss or a paper towel in airtight containers inside the seed storage refrigerator for 1 – 12 months depending on the requirements of each species. Some seeds require double dormancy; one cold period is not enough for these slowly germinating species. After the first few months in the refrigerator, they need to warm up for a couple more months and then go through a second cold cycle. The seeds are then ready to be planted in warm soil after the last frost date in spring. It is possible to follow nature’s process more directly and sow seeds outside either in-ground or in containers during the fall, but be aware that they are not as protected from being eaten by animals or killed by a late freeze.

At the Reserve, we start the process in our seed chamber with a system that can be easily set up at home for horticultural enthusiasts using a baker’s rack, UV lights and heat mats. Right now, we are stratifying milkweed, hibiscus, lobelia, Turk’s cap lily, magnolia and strawberry bush among others. We are also germinating native azalea seeds (pinkshell and Gregory Bald hybrids), red spruce as well as other native plants for our annual Plant Sale in the fall. This early start will provide a longer growing season than naturally occurs at our high elevation.

For those of you eager to stay connected with your garden throughout the year, we offer some timely tips for chilly days:

  • It has been said that some of the best gardens are built in the winter by a fire. We suggest you spend some time simply walking through and around your garden during this bare-bones season to observe at the deeper level, and then warm up inside while you sow your plans for the coming growing season.
  • Make note of what worked and what didn’t during the last season so that you can have a more fruitful garden in the coming year.
  • Meet with an arborist to learn more about how to best care for your trees and consider winter pruning of crossing branches, damaged limbs or canopy release.
  • It’s a great time for grading projects should you want to transform the lay of the land for improved water flow (away from your foundation), erosion control or simply for an enhanced design.
  • Winter is also a fine time to remove invasive species, especially English ivy. No mosquitos will bother you and the robust workout you get from tugging at those tough roots will keep you warm.
  • Finally, when you’ve had all you can take of the cold, it’s nice to warm up back inside and peruse catalogues for seeds, bulbs, tubers and anything else you plan to add this spring.