With a lot of man or woman power! That is not a joke either.
While visiting Chanticleer this June, I attended one of the Pennsylvania Horticultural Society’s educational seminars on Biennials and Self-Seeders. While a very enjoyable two hours, it really offered very little new information to experienced gardeners or landscape professionals. I am not sure what I was expecting, but the tips were very time-consuming and commonly known.
The first tip for controlling aggressive self-seeding plants was to hand dig the numerous seedlings in Spring. One advantage to digging them up was to move them to a new location if you choose. I do this with both perennials like pincushion flower or penstemon and annual seedlings, like Verbena bonariensis, butterfly weed, cosmos and snapdragons.
The second tip was collect the seed when mature to broadcast where and when you want them. I have done this also with various plants, like corn poppies.
On the same thought, saving seed to pot up over winter was a tip. This one is just too time-consuming and inconvenient only having grow lights and no greenhouse, but I do pot up perennial plants to overwinter outside under our snow cover. My back garden is filled with potted plants right now, many being sent off to new homes.
Potting up saved seed or perennial plants is a good way to have the plants appear in the garden where you need the color or interest. While good advice, methods they use for their Elevated Walk, cutting, gravel and meadow gardens still entailed quite a bit of work. As pretty as it is at Chanticleer, many beds beside the new the new Elevated Walk were a bit over-grown and under culling procedures. To their credit, the many gardeners responsible for their assigned beds were thinning out the beds, weeding and digging out sizable areas to replant. I will show more coming up.
One problem they run into in the very full gardens is some of the desired self-seeders were not self-sowing as much as they wanted, or seeding only in places where they shouldn’t. Below is South African Foxglove. Some were blooming in the cracks of the walkway by the pool. They could not get the plant to reseed where it was planted or the seed broadcast. Most probably, it needs extremely gravely planting medium and prefers the dry, sanded cracks of the paving.
Verbena bonariensis also seeds where it likes, not where you want. Their gardeners and myself have the same problem with this plant. One explanation, the seed does not reach bare soil exposed to sunlight in which to germinate.
In some cases, the beds at Chanticleer are too full and the seed has little or no bare earth on which to germinate. The gravel garden was one such place. The gardener had to thin the garden to allow bare earth to greet the warm sun. As you can see this is a never-ending process. An advantage to thinning? They get to edit the garden and have desired plants artfully interspersed throughout, like which was well illustrated in the gravel garden.
Controlling weed seed is also a huge chore since no chemicals or pre-emergents are used in the gardens. There was no tip on this one, just, pull, pull, pull. Some of the desired plants like Orlaya grandiflora, shown below by a Chanticleer intern, become a “weed” with their aggressive self-sowing.
Some these plants included in the gardens might be considered weed plants (or wild flowers depending on your perspective). It all depends how much space they inhabit or how many new places in which they might pop up. It really is a constant battle.
What I did learn was a few plants that were interesting, like the South African Foxglove. I doubt it would seed here in all the clay. Some of the recommended plants are already in my garden. Delphinium exaltation is native and is a quite beautiful self-sowing plant. In these gardens it was a bit aggressive. In my garden, it is not be due to stratification since I have had this plant before and it disappeared on previous occasion.
Some seed species undergo an embryonic dormancy phase, and generally will not sprout until this dormancy is broken, or some seed may not survive winters here. Seed scarification results from a seed’s hard seed coat being impervious to water and also aides in a plant’s dormancy period. Freezing helps this process to happen. In my garden, Nasturtiums and Cleome germinate freely after a good freeze.
Good self sowing annuals I use include verbena bonariensis, zinnia, fennel, dill, and cosmos. But watch fennel and dill, either will be everywhere. I keep those herbs potted. Chanticleer also used dill that ended up in walkway cracks. Penstemon, butterfly weed, ragwort, goldenrod, pin cushion flower are some perennials that reproduce easily and freely.
Soil composition and texture is another consideration to whether plants can move from place to place or zone to zone. The instructor did not get into these biological or horticultural processes, but since the attendees came from various places around the country, it was worth mentioning. I purchased a native Jack-in-the-Pulpit which I hope will naturalize for instance. It is not as pretty as the hybrids, but just might make a nice companion for my fern and hosta.
Mt . Cuba? I have some tips coming from there soon. I don’t just post photos, but add something you might not know about these phenomenal gardens. Next, the month in photos at my garden and a look at some of these self-sowing plants.