Which? Gardening is a prestigious British gardening magazine. American readers could think of it as a sort of horticultural version of Consumer Reports. In this month’s issue there’s an article by one of Britain’s top plantspeople and nursery growers, Bob Brown of Cotswold Garden Flowers, about growing perennials from seed.
In it he says: "My experience is that seed of perennials will only reliably germinate if it's sown immediately, certainly within the month. If it gets as far as a packet or a seed catalogue it's already too old." And also... "My advice generally would be not to buy seed of perennials.". Yes, he recommends home gardeners not buy seed of perennial plants. The only exceptions he mentions are "lupins, delphiniums, cactus and other succulents".
Now I have a huge respect for Bob: he’s a fine plantsman, a fine grower and as a judge of the Royal Horticultural Society’s plant trials his insight and unvarnished opinions are invaluable. But, in this case, I’m afraid he’s just plain wrong. The only perennial seeds to buy from catalogues are delphiniums and lupins? I don’t think so. Over the years I’ve raised thousands of perennials from bought seed, fresh seed and seed found in brown paper bags in the back of the shed. Most of it comes up.
It’s a shame that Bob’s recommendation could prevent gardeners from growing a vast range of fine garden plants.
Richard Oliver, the UK manager of Jelitto Perennial Seeds, whose catalogue lists seed of over 3700 perennials and who’ve been in business for over fifty years, disagrees with Bob: “His comment is frankly wrong. Some of the seed packet stuff may be too old, or more likely, have been stored in really unsuitable conditions, but his comments are otherwise nonsense. For example: Dianthus, Achillea (above, click to enlarge) and Telekia, among others, can germinate over 90% within one week even if stored longer than 10 years. Most of our perennial seed has been tested and has a germination rate of about 70% or more. All the world’s seed banks would be useless if he was right.”
And Derry Watkins agrees. For twenty years she’s run Special Plants in Wiltshire where she not only raises a huge range of perennials from seed but teaches seed-raising techniques to gardeners. Derry told me: “I think he’s mad. Most perennial seed will germinate after 5-10 years if kept cold and dry. It may not be quite so quick or prolific, but you get the plants you want. Fresh is best, but with good storage conditions, old is fine. I sow 2-3 year old seed all the time without a problem.”
Across the Atlantic, the same view prevails. Allen Bush, the Director of Special Projects in the American office of Jelitto Perennial Seeds reminds me: “What to make of 30,000 year old seed of Silene stenophylla? Perennial seed does germinate.” Frozen seed of Silene stenophylla was found in Siberia in 2007 and scientists from the Russian Institute of Cell Biophysics announced last year that they had regenerated plants from seeds carbon dated to 31,800 years old.
I also asked top American grower and plantsman Tony Avent of Plant Delights for his view. “There are certainly some seeds that will not store well, and others that loose viability when they are not stored properly. But most plants in the Asteraceae (daisy) family, for example, won’t even germinate fresh since they require a long after-ripening period.”
So… Sorry Bob, but we don’t agree. In your article you emphasize raising plants from seed collected from our own, and our neighbors’ gardens. Fine. But most commercial seed suppliers know how to store seed correctly, and test it regularly, so that when it’s delivered it’s ready to sow, and ready to grow. OK, some needs special treatment. But advising gardeners not to buy seed of perennials at all cuts them off from an economical way to raise thousands of fine garden plants.
The pictures (click each to enlarge):
Achillea 'Summer Berries' - Mix of fruity colors, easy to raise from seed, germinates quickly.
Delphinium 'Guardian Blue' - One of the best blue delphiniums to raise from seed. Bob excludes delphiniums from his "don't buy seed of perennials" advice.
Rudbeckia fulgida var. sullivantii 'Goldsturm' - 99.9% true to type, easy to raise from seed, germinates quickly.