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Re: [PRIMROSES] Table top greenhouse & Primrose

Speaking about the Primrose part of your question only ( mostly because I
plant Hosta seed outside and have really never tried  under glass ),
Primrose will NOT germinate at temperatures much above the low 60's ( F )
18 C.

Commercially, in my part of the world at least, they are sown in unheated,
open ended, poly covered hoop houses with about a 75% shade cover.
Alternate freezing and thawing is required for some species to germinate.
High temperatures prevent germination. They need cool growing temperatures
and a lot of air movement. None seem particularly bothered by below
freezing temperatures. Quite a number of species originate in high
mountains and lie under many feet of snow until spring.

I have had great luck in my climate by carefully scattering the fine seed (
I aim for about an inch a part; 15 to 18 seed per 5" pot ) on the surface
of a very thin layer of granite grit, which tops the soil in a 5" plastic
pot. I DO NOT cover the seed as it needs light to germinate. The flats of
these pots go on the ground under the overhang of the eaves of the house in
heavy shade. The overhang keeps most of the rain off of the flats. They
need to be damp and moist, not wet ( it rains a whole lot in Oregon in the
winter ). The seed germinates erratically with a lot showing in February,
March and April. Seed is sown as it arrives from December to February.
Germination continues into the second year and sometimes the third. Don't
throw the pots away too soon. I wait to transplant until at least four
leaves show. In the thinly sown pots I sometimes do not transplant until
the year following.

Primula want both air and moisture at their roots. This means good drainage
with moist soil. I use a mix of one third granite grit ( chicken grit from
a feed store works great ), one third peat moss, and one third potting
soil. I'll amend this up to 50% grit for some hard to grow species. Other
than baiting for the miserable slugs ( who will think you've opened a good
delicatessen for them ) and watering them during dry weather, I really
don't pay too much attention to them. Thompson and Morgan have an OK
selection but the seed exchanges of many plant societies lists a number of
very choice species and hybrids. All are worth growing. It is a vast and
fascinating plant family. Good luck and enjoy!

With Best Regards,
Steve

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Stephen J. Vinisky
21700 S. W. Chapman Road
Sherwood, Oregon, 97140-8608   USA
USDA Zone 8a  - 750 foot elevation, 228 meters;
Minimum Winter Temp: 15 deg. F;  -10 deg. C
Phone (503) 625 - 3379     FAX (503) 625 - 3399
e-mail: stevev@europa.com

Of all the things I've lost in my garden, I miss my mind the most. SJV

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At 11:27 AM +0000 on 12/23/97, Garden Nut wrote:


> I have 2 tabletop greenhouses with 70 degree heat in their bottoms.  Has
> anyone found this type of setup advantageous when sharting hosta or
> primrose seeds?  Since these are "shade plants" I am trying to decide if
> their want warmer or cooler soil for germinating.  Another alternative
> would be to put both outside in the coldframe and let nature handle
> things.  Suggestions?
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