How deep to plant

Pulaski, IL

If there is no depth listed on the package of seeds, should they be surface sown or planted according to the size of the seed?

Greeley, CO(Zone 5b)

You could check the plant files and see if there is anything there. If not and you don't want to do an extensive web search I would go by the size of the seed. What are you planting?

Pulaski, IL

I went back to the JL Hudson website because the package said the info would be in their catalog (I ordered the seed from them online) I couldn't find any more info than I had read when ordering so thought it would surely be on the seed pack. I've ordered from several different companies but this is the first from them. It has always been on the package with other orders. I also went to another website that is helpful with seed germination times, but it didn't give the depth either. I need the depth to plant for Baptisia: Leucantha, Geraninum Pratense. Lilium Asiatic, Cephalaria Gigantea and Helianthus Annus. Several others I ordered did say to plant shallow or barely cover. I am also wondering if any of these need any special tx. such as bottom heat or cold.

This message was edited Feb 21, 2011 8:07 PM

Greeley, CO(Zone 5b)

I order most of my seeds from JL Hudson and find that there are times when the directions in the catalog are not clear at all. Have you checked the plant files yet?
Most plants germinate faster w/ bottom heat, even the ones that will germ in cooler temps like columbine and such.

Pulaski, IL

Ok thankyou. I did try several sources and never did really find what I needed. I'll try the plant files again and see if I overlooked anything. I use bottom heat on a few things but have been afraid to use it on Columbine since one package states not to use bottom heat. In the past, I have had one company say to put the Columbine in the fridge for several weeks where others do not mention refrigeration. The seed I ordered this year was a rather new variety and it said no bottom heat. I have had mixed luck with Columbine, with and without cold TX. What variety did you germinate with bottom heat? Also, have you ever tried to start Lantana from seed? I have tried for several years with seed from several different comp. with no luck even with soaking, nicking, and bottom heat.

Greeley, CO(Zone 5b)

I have tried Lantana w/ no luck either. I was going to try again this year, but forgot about it until just now. I found w/ some hard to germ seeds w/ hard shells you can soak them in very hot (almost boiling water) and let them cool for 12 hour then plant. That is how I got my Angels Trumpet to germinate. Look in the back part of the JL Hudson catalog and there should be some other options as well as what I told you.
As for Columbine, it depends if the seeds have been treated. If they have you can just plant them, if not put the seeds in wet paper towel and refrigerate for 3 weeks then plant. I only have the heat mats on at night since they are in the coldest part of the greenhouse and so far I have about 10 sprouts (after about 1 1/2 wks) compared to 1 sprout in the tray that is not on a mat.
Last year I had really good luck in the house w/ them, but since I got the gh I thought I would be nice and not cover the counter tops w/ plants. I do have a flat in the laundry room closet, but that's it.
I would say experiment. It is not just a learning experience, but it is quite fun to see what works best for you.
I wish I still had my catalog so I could look to see if there is anything there, but I cut out what I needed for the plants I ordered and taped it to the packages. Did you check to find out if you could request a catalog?

Casper, WY(Zone 4a)

A general rule is that very small or dust like seeds need to be surface sown. Those that are larger should be planted 3x their size in depth.

You can also plant seeds in a trench made in the soil. That way, the soil is tucked against them but not completely covering them

Pulaski, IL

Ok thankyou both for the tips and advice. Sounds like your methods have all worked for you and I will have to try them especially the trenching and hot water soaking. I do soak some seeds but have probably not had the water hot enough on the really hard shelled seeds. I don't have a JL Hudson catalog, I just went to their website and ordered online. Seems like they might have said they would send a requested catalog. I went ahead and planted some of each variety of seed, trying to go by what I remembered about similar varieties I had planted in the past or by their size. So far a few of the Geranium Pratense Striatum, both the blue and white Campanulas, and all of the Helianthus are up. The Helianthus I wasn't too worried about since it is in an easy to grow family. The white Baptisia, Asiatic lilies, Clematis and the Cephalaria are not up yet. The Columbine seed was from a different company and it is not up yet either. I will try the paper towel and fridge method with the rest of the seed. I have a blue Baptisia I grew from seed years ago, and trumpet lilies that were from seed, a different variety of Clematis from seed and also have grown the same geranium from seed, but it got choked out eventually by tougher ground covers. I wish I had kept records so I would have that to draw from also. Every year I say I am going to start a journal but the closest I get is writing down what is in each row and the dates planted. I have a small greenhouse but I don't want to spend money to heat it, so I start everything in the house and then move everything to the gh to repot and grow on when the weather warms. Everything I have grown has mostly been trial and error but as you stated onyxwar, it is fun, especially when you have success and are rewarded with blooms that didn't come from a commercial source plant already in bloom.

Greeley, CO(Zone 5b)

Good luck and keep us posted.

Pulaski, IL

Not sure if this is still being followed since last post has been over a month, but waiting to see what would finally germinate. I put the Clematis seeds in the fridge for approx 3 weeks and then returned to room temp. Several have came up. The rest of the seed finally germinated except for the Cehphalaria. That was the only seed from J.L. Hudson that did not have any germination. I even managed to dump that tray of seeds which tossed out mostly the individual pellets of the Columbine and mixed the colors up but a few did germinate as well as the Baptisia. The Campanulas were already up and survived the drop. I have a couple of Asiatic Lilies which were very slow to germinate but after using bottom heat got 2 out of 6. All of these are several inches tall now as well as the Geraninum Pratense.and the Helianthus. I tried the baggy method with the rest of the Clematis and the Lantana, but have not seen any sign of sprouting yet. I'm not sure how long to give them or even if I did it right. I am excited to see what the flowers look like providing they survive the first year since it is unlikely they will bloom this year. That is the downfall of my planting zone. Perennials rarely bloom the first year from seed, and with our heat and lack of rain, it is becoming more of a challenge every year to grow them on.

This message was edited Apr 19, 2011 1:52 PM

Casper, WY(Zone 4a)

STosh, I am glad that you are getting some success. As far as the Clematis, they can take a long time before sprouting because they need stratification (cold-moist) I have sown them and left the pan covered outdoors all winter. You can use the fridge also.

Before you soak seeds, they need to be nicked so that they can absorb the water. If you don't, the soaking does nothing.

The Hudson website does offer germination info. Two other great sites are:

Pulaski, IL

Thankyou Blomma for the tips and websites. It always helps to hear from someone who has experience with seeds that are hard to germinate and have other gardening sites to refer to.

Everett, WA(Zone 8a)

When I'm doubtful about depth of planting, I'll often cover them with fine vermiculite instead of soil, and put them on the deep side of whatever I guessed.

I think it is easier for sprouts to push through vermiculite than soil, that might get crusty or hard.

I have seen rules of thumb like "2-3 times the seed's biggest or smallest dimension".

Or, with more work but fewer guesses, you can sprout on a coffee filter in a plastic bag, and plant the sprouted seedling! I think that is called "the Deno method".

I would try to look up a species to learn whether the seeds "need light" or "need dark" to sprout.
At the same time, make note of what temperatures they prefer and 'expected days to emerge'.

Ones that are said to need cold, moist stratification don't always need it! Or more of them may sprout that way, faster. However, I find that seed packets sometimes hate to tell the customer they need to take extra steps ... more work equals fewer sales.

Pre-soaking Salvia seeds overnight gave me much better results.


Pulaski, IL

Thank you for your tips also Corey. I do use Vermiculite when the pck says to cover lightly. I think you are right about the instructions on the seed packets. I have bought seeds from different companies. Some give really good instructions and others very little. For Columbine, some say cold first and others do not. One year on one variety, it did not say cold and I got 0 germination. Maybe it was just the variety because with another variety I got good germination without cold. Trial and error sometimes, but it helps to get feedback from others.

Casper, WY(Zone 4a)

Seeds that need light are small or tiny seeds. It is not to be taken literally. It just means that they should not be covered because they would not make it to the surface when sprouting. Seeds have a built in food supply to carry them throught until they have produced roots. If planted too deeply, tiny seeds would exhaust that food supply and perish.

Columbines do best with stratification (moist cold). I have yet to see a seed package state that. It always makes it sound so easy.

Corey, yes it is the Deno method and the only method I use for perennials, unless the seeds are tiny. I always nick, then soak overnight in hand hot water first.

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