I have a bed which we dug 2 years ago and added Anise Hyssop Pearly Everlasting and Virginia Mountain Mint.All of which is doing very well, but the soil in the bed has subsided and is now 4 ” below the adjacent lawn can I just add soil or do I need to lift and replant the plants- can I do it now, or do I need to wait until spring? I have soil I got for another bed so want to get it out of the bag!
Pearly Everlasting (Anaphalis Margaritacea), Anise Hyssop (Agastache foeniculum) and Virginia Mountain Mint (Pycnanthemum virginianum) are all perennials native, or established, in Ontario.
As our region moves into the autumn and dormant winter periods, now would be a good time to augment, and amend your plants’ somewhat compacted bedding soil. Unless you feel the need to relocate for some other reason, your perennials’ root systems do not need to be disturbed, or lifted out, as they are now well-established.
We suggest the use of organic amendments, that can be combined with your bag of soil: leaf mulch, compost or well-cured manure. Without knowing the size of your bed, or the number of plants growing within, the process of in-filling 4″ can be started any time now, and you can profit from the discarded leaves of deciduous plants, shrubs and trees. Rather than waiting 2 years, this is a good cultural practice to employ each year — your plants will thank you!
Please read our Toronto Master Gardeners advice on the uses of Compost vs. Manure
For further in-depth reading, please also see Living Soil, Healthy Garden from the University of Minnesota Extension.