Jack Frost, Garlic and Cover Crops.

Rumors of frost were heard in northern Bucks County last Saturday (Oct 23) but for most of Southeastern PA the growing season continues uninterrupted. In fact, even where light frost occurred, as in my backyard, I still see many cold sensitive plants surviving. My fancy new minimum/maximum thermometer at the Extension office in Doylestown says 35 degrees F is as low as it’s been here.

So, it is clear we have not had that killing freeze that signals a definite end to many aspects of gardening. But official, long-term records tell us that we are on borrowed time… the median (equal number of occurrences on both sides of the question) frost date in Bucks County is October 6.

Sure enough the tomatoes and peppers that are still hanging on out there look pretty rough. The accumulation of summer diseases combined with short days and very cool nights makes most of us yank them out of the garden. In fact, smart gardeners ruthlessly pulled these plants a month ago and planted lettuce, spinach, broccoli rabe and other late season crops. Or maybe you even sacrificed the late season tomatoes altogether in return for a fall crop of broccoli, cabbage and cauliflower by transplanting these “cole” crops in late August or early September.

Even if you waited until now, there are a couple final crops you might consider. Cover crops and garlic.

Cover crops are plants that we establish to protect soil from compaction, to soak up leftover nutrients and to build soil organic matter. The most common fall cover crop in our area is rye. Not ryegrass but cereal rye, sometimes called winter rye. It germinates quickly in the warm, fall soil and makes a vigorous overwintering cover that resurges in the spring. In fact, you have to prepare to manage this cover crop or it will become a beast that is hard to incorporate. Plan to spade it under in April before it begins to bolt and go to seed. You’ll be rewarded with a great shot of soil organic matter, nutrition and biological activity. Rye is not the easiest seed to find but old-time feed stores will a have it. Seed it at about 3 to 4 lbs per 1000 square feet into well-worked soil. It is a large seed so try to get it about an inch deep.

Last but not least is garlic… the last edible crop we plant in the garden. Our goal is to have the garlic cloves root but not make too much top growth before winter sets in. This allows for a petty wide planting window. I shoot for Columbus Day in mid-October but planting until the end of October, or even a little later is not a problem. Get “seed” at a local farmers market selling locally grown stuff or order a variety grown in the Northeast US for best results. See this link for more details, page 27.

Jack Frost is coming but the gardening season continues.

Montauk Daisies, Nippon Daisy… Nipponanthemum nipponicum

Mother Nature saved some of her best work for the end of the growing season with the Nippon Daisy. Also commonly called the Montauk Daisy (because it is commonly found on eastern Long Island), its Latin name, Nipponanthemum nipponicum, makes it pretty clear that this plant is native to Japan (Nippon). Plant lovers may also know it by its former Latin binomial, Chrysanthemum nipponicum. By its current classification, it is the only member of its genus, one of 477 genera in the Aster Family. So much for the nomenclature.

Almost precisely one year ago, I was on a busman’s holiday in Rhode Island, looking over the Kathleen Mallon Memorial Demonstration Gardens on the campus of the University of Rhode Island. They are created and maintained by Master Gardeners in that state and named for an Extension Educator who was instrumental in launching the Master Gardener program there. I was knocked out by the brilliant white show of flowers from Nippon Daisy. My plant pal, Mary Jane, quickly identified it and told me that they were as common as clams in Rhode Island. Then I started noticing them everywhere in Costal New England.

Back home, the Nippon Daisy faded from memory until I was in a very good local garden center this summer and asked if they had ever heard of them. I don’t see them used much in SE PA. The plantsman at the garden center agreed but said he was beginning to get inquiries about it. Sure enough he had a few containerized plants and they are now lighting up my fall landscape.

Nippon Daisy is hardy in zones 6-9 and is a rugged plant. It tolerates dry sites, does best in full sun and makes its floral display late in the growing season. It will grow about three feet tall and wide and requires some simple/easy pruning for best performance. They can become “leggy”, that is, produces naked stems but with a bit of pruning the plant can be kept a bit more compact. Plan to cut them close to the ground each spring. Most landscape design advice is to plan for something that grows a bit lower in front of Nippon Daisy to hide its bare legs as the season progresses. Some references say deer don’t care much for it and it has stood up to a modest test in my landscape. The floral display beings in late summer and lasts late into the fall. White is the word. Maybe it is the contrast of white with the reds and golds of our fall foliage that makes it so attractive. Makes a good cut flower, too.

Reading about this plant, I learned that the famous plant breeder and legendary, pioneering geneticist, Luther Burbank hybridized this species with other closely related species to create Shasta Daisy and other popular cultivars which we still enjoy. Apparently, it was the brilliant white that made him choose Nippon Daisy for his work.

It seems that my revelation about Nippon Daisy would cause a chuckle among coastal gardeners but until I see more of them in Pennsylvania landscapes, I will continue to talk up this great plant.

It’s not too late to search for this fantastic daisy in local garden centers. Call it Montauk, Nippon or Nipponanthemum nipponicum, this plant is worth a look if you are in the market for an outstanding fall bloomer for a hot, dry site.