Germinating Sassafras seeds - failure - what is wrong?

[Harry Haller]

Hello,

Can you tell me what I'm doing that is so wrong, and how to do it right?

Last year I tried to grow Sassafras seeds with no success. This year I will try again!?! I followed the instructions on the seed packet approximately.

I soaked the seeds in tepid water. After 12 hours, I removed the (now wet) berry. I continued soaking for another 12 hours. I cleaned the seed coat by scrubbing lightly with a plastic kitchen scourer (to remover any remaining berry tissue). At this time nearly all the seeds had sunk to the bottom of the water. I then divided my seeds into 2 equal portions (discarding the seeds which floated on top). I soaked half the seeds in fungicide suspension for an hour. I used "Supercarb", at a dilute concentration of 1g/450 ml water. This contains "carbendazim plus activator". I placed the seeds into 2 used Petri dishes containing moist sand, both in the same plastic bag (to prevent them drying out). After cold stratification in a fridge, at a temperature of about 2-5 C for 4 months, I noticed that the seeds without the fungicide treatment had (as expected) gone mouldy. I planted my seeds out into 2 containers (last March). One half of the seeds (half of the treated ones and half untreated seeds) were put in a container with sand and the rest of the seeds into a container with John Innes No 1 compost. So I had 4 series of seeds; each series given a different treatment. These were all put in a cold frame. I ensured that the seed containers did not dry out by checking the moisture (by touch) and watering when I thought it had got too dry. None of the seeds germinated.

I missed out the mulching, (described below). Is it that important?

Sassafras is a dioecious plant. Is it possible that I had a bad, e.g. an infertile, batch of seeds?

I am at a loss to figure out what I did wrong. This method of soaking in fungicide has worked well for other seeds both those requiring cold stratification and those that don't.

Most of the instructions I've read on the Internet for growing Sassafras seeds mention cold stratification but not all describe how it should be done. Some of the instructions say that 2 months of stratification at 2-5 C is sufficient.

The original reference on that topic (Bonner and Maisenhelder [ref. 1] ) says: Germination:- The seeds exhibit strong embryo dormancy, which can be overcome with moist stratification at 41° F. (5° C) for 120 days. Germination can be tested in moist sand or other media at temperatures of 70° to 85° F. (21-29° C) for up to 120 days.

As I said I am down but not out. I have ordered a new batch of seeds and will try again. Apart from mulching (with leaves?) and trying different fungicides, is there anything else I should try? For instance, should my cold frame be in the shade or in the sun? What is the sense in trying to germinate seeds in sand? I noticed that the sand dries out quite quickly. I only tried sand because the guys who did the initial trials, using 120 days cold stratification, also used sand. They published their results in the

This year I will start 8 series (for planting next spring). I will try out 2 different types of fungicide and a quarter of the seeds will get no fungicide at all. I propose:

Series treatment (fungicide, cold stratification period):

1 no fungicide, 2 months 2 no fungicide, 3 months 3 Supercarb, 2 months 4 Supercarb, 3 months 5 Supercarb, 4 months 6 Dithane 945, 2 months 7 Dithane 945, 3 months 8 Dithane 945, 4 months

I will put my cold frame in direct sunlight, all series will be germinated in John Innes #1 and mulched with leaves. Are there any other recommendations?

I got my seeds from a recommended US seed supplier: "The Sheffield Seed Co." Here are the instructions provided on the seed package:

Sassafras albidum db. Source 2004, Missouri.

Scarification: Soak in water, let stand in water for 24 hours. Stratification: cold stratify for 120 days. Germination: sow seed, 3/8" deep; damp the soil, keep moist, mulch the seed bed, can be sown outdoors in the fall for spring germination. Other: remove seed from fruit prior to treatments.

References:

1) Bonner, F. T., and L. C. Maisenhelder. 1974. Sassafras albidum (Nutt.) Nees sassafras. In Seeds of woody plants in the United States. p. 761-762. C. S. Schopmeyer, tech. coord. U.S. Department of Agriculture, Agriculture Handbook 450. Washington, DC. 2) 3)

4)

[Doug Kanter]

How about putting some of them in the freezer and seeing if they do better than the ones in the refrigerator? Sassafras grows where I live, and winters get down to nearly zero F.

[mel turner]

[snip long description of efforts so far]

Googling for "Sassafras + seed + propagation" finds quite a bit that sounds basically similar to your information, e.g.:

: "Propagation is fairly simple from seed. If you can obtain it, fresh seed will give the best results and this should be sown immediately in a cold frame. It should germinate in the spring. If you can only obtain stored seed then this will need four months cold stratification at 4°c. Soaking the seed for 24 hours in warm water and then mixing it with some damp compost and placing it in the salad compartment of the fridge for 3-4 months should suffice. As soon as they are large enough to handle, prick out the seedlings into individual pots and grow them on in the greenhouse for at least their first winter before planting them out. Give the young trees some protection for at least their first winter outdoors[K].

Suckers can be dug up in late winter. If they are well-rooted they can be planted straight out into their permanent positions but if the root system is rather sparse it is best to pot them up and place them in a lightly shaded place in the greenhouse until they are growing away strongly. In addition root cuttings can be taken from the suckers. These cuttings should be about 1 - 2cm long, they are taken in December and planted horizontally in pots in a greenhouse. Grow them on for their first winter in the greenhouse before planting them out into their permanent positions".

much the same as the above.

: "Sassafras albidum , Sassafras ,zone= 4 , sow 4m @ 39ºF, move to

70ºF for germ."

: "Propagation Method: Seed Product Type: Container (plug) Propagule Processing: Seeds exhibit physiological dormancy. Pre-Planting Treatments: Seeds are cold stratified for 120 days and germinate at 30/20 C." [gives refs]

Hope that this helps.

cheers

[bae]

You've been given good technical advice. If you don't mind, I'll add a few fairly ignorant comments.

(1) If you haven't thrown all your pots of no-shows away yet, bury them in your garden for the winter. It's amazing what can come up after a year or two on occasion.

(2) It's quite possible that despite doing everything right, the seed you received was non-viable. I don't know anything about the company you ordered from, but for many species, if the seeds aren't carefully handled with suitable temperature and humidity from collection until you plant them, germination can be dismal. While some companies are very careful, others feel that as long as the seeds they send you are from the species named on the label, they've done their part. Seed could be old, could have been exposed to excess moisture and then redried multiple times, could have been exposed to excess heat or dryness, etc. It also may not have been mature when collected, or otherwise defective -- e.g. empty or aborted or poorly developed seed.

The times I've had the most success with seed of wild plants is when I've collected them fresh, when the plant is dispersing them, and planted them immediately where the temperature cycles and precipitation they are adapted to can set off germination as the seed "expects". So I'd recommend that you collect your own seed, and plant lots. If sassafras doesn't occur in your area, see if you can find someone to send you fresh seed from an area with a climate similar to yours. You might also consider planting the seed you have now shallowly in a high humus soil (leaf mold would be ideal, since sassafras is a forest understory and edge species) and sinking the pot in a sheltered spot in your garden, under a shrub would be good, perhaps covered by a few handfuls of autumn leaves. If squirrels or mice are a problem, cover the pots with screen. Note that seed may keep germinating for several years if you put the pot back in the ground and keep it watered after you remove this year's seedlings.

This is the ultimate low-tech approach, but it has the advantage of managing factors that nobody may even be aware of. Once you go with controlled conditions, you have to control everything. It's not good if you need very reliable, repeatable results, but it has the advantage of simplicity for an amateur.

Sassafras is a wonderful tree, beautiful and fragrant. I hope you have better luck in germinating it next time, whichever method you use. I'm outside its range, or I'd offer to collect seed for you. If your objective is just to get a few trees, sassafras suckers like crazy, and getting a few pieces of freshly cut root, kept cool and moist until planted, may be the easiest method. Or perhaps you can dig up suckers or seedlings from a fencerow or the edge of someone's woodlot (with permission, of course).

Good luck, and let us know what happens.

[Harry Haller]

I'll get a thermometer to check my freezer temperature but it seems a little too cold in there. I wouldn't want to go below -5 for too long. It may get very cold where you live but I doubt it stays that cold for

120 days! Nevertheless I'll consider that for a percentage of the seeds for, maybe, a month.