FROM THE BOARD 



Growing Perennials from Seed 



Peter van Berkum 



Several years ago, we decided to 

 get more involved in growing 

 plants from seed at our perennial 

 nursery. It may seem odd tiiat we 

 waited tiiis long, but when we first 

 began, we were specifically inter- 

 ested in vegetatively propagated 

 cultivars. As we got more involved 

 with native and species plants, we 

 decided to work with seed. 



We produce from seed any plant 

 that doesn't need to be asexuaily 

 propagated to remain true to type. 

 However, if a variety is available 

 commercially in small plugs, we will 

 buy them in instead of germinating 

 them ourselves (By small, I mean 

 350-to-400-count plug trays. 



The seeds are either bought in 

 or collected ourselves. We collect 

 seeds ourselves if they need to be 

 fresh for successful germination. For 

 example, some seeds have a carun- 

 cle, a fleshly-like substance going 

 from end to end — like the threads 

 on a football. (Trillium and blood- 

 root seeds have this feature.) The 

 caruncle's function is to attract in- 

 sects. Once it dries out, the seed 

 may go dormant for two-to-six years. 

 So these seeds must be collected 

 and sown immediately. We collect 

 other seeds simply because it's so 

 easy. We have the stock plants; the 

 seeds set; we collect them. 



Next, you have to figure out what 

 sort of conditioning (if any) is re- 

 quired for germination. Most peren- 

 nials are not like annuals that can 

 simply be sown and will germinate 

 in one-to-three weeks. Perennials 

 have internal mechanisms that pre- 

 vent them from germinating when 

 they cannot grow. Do the seeds 

 need light to germinate? (Most wet- 

 land plants do.) Do they need a 

 cold period? (Many seeds that ripen 

 in late summer have an inhibitor 



J. erennials 



have internal mechanisms 



that prevent them 



from germinating 



when they cannot grow. 



Do the seeds 



need light to germinate? 



Do they need a cold period? 



Or do the seeds need 



a warm period followed 



by a cold? 



And some seeds 



need no conditioning at all — 



sow them in spring 



and up 



they come. 



C/5 



that won't let them germinate until 

 they've sat through a winter, this 

 prevents them from germinating in 

 the fall and being killed by the 

 cold.) Or do the seeds need a warm 

 period followed by a cold? (This 

 can be the case with some plants 

 whose seeds ripen in early-to-mid- 

 season — again, a mechanism to 

 postpone germination until after the 

 winter.) And some seeds need no 

 conditioning at all — sow them in 

 spring and up they come. 



We try to get all the seeds with a 

 particular type of conditioning started 

 together so we can put them through 

 their requirements as a group. Norm 

 Deno of the University of Pennsyl- 

 vania has written an excellent book 

 called Seed Germination. Theory and 

 Practice that specifies the require- 

 ments for many plants. It's available 

 through Penn State University. 



How do we give the seeds the 

 conditions needed to break dor- 

 mancy? With many seeds requiring 

 cold or warm/cold, we collect them, 

 sow them immediately into flats, 

 and put them outside. This way 

 they get whatever conditions they 

 require and usually germinate after 

 the first winter. You can play around 

 a little more by putting the seeds 

 in tight baggies with barely moist- 

 ened potting mix. The baggies can 

 be easily brought from the refrigera- 

 tor to room temperature and back, 

 giving whatever combination of 

 warm and cold you may want. A 

 technique we plan to try is putting 

 the seeds on moist paper towels in 

 flat dishes with tight lids. We can 

 move these from warm to cold as 

 required and be able to continually 

 check the seeds. When any germi- 

 nate, they can be picked out and 

 planted. 



Growing herbaceous perennials 

 from seed is both an art and a sci- 

 ence. We find it to be both a chal- 

 lenge and an economical way to 

 produce a lot of plants in a small 

 area. Each year we learn a few new 

 tricks for old varieties and get 

 stumped by a few new ones. This 

 helps keep the nursery business in- 

 teresting. 



Wan Berkum Nursery is at 4 James Road 

 in Deerfield. Peter and Leslie can be 

 reached at 603-463-7663. 



FEBRUARY & MARCH 



