Need help with growing oak seedlings.

[thescienceguy]

New member with several questions. Hope someone can help.

I am the High School Science teacher at a small school in northern wisconsin. I collected over a thousand Bur oak acorns last week and am seriously contemplating growing them in school as a science project over the winter. If successful, the students would sell the seedlings this spring as a way to raise money for the science department. With the state forced budget cuts, it is a miracle we are still open.

I have been doing a lot of research on the web about starting oak in containers, and I think I have the logistics of the project figured out. I just have a couple specific questions.

1. It seems as though the length of the tap root is the problem in raising them in containers. If we germinate and grow them in 16 oz. foam cups, starting in October, is the length of the tap root going to cause a problem before spring?

2. Can the tap root be cut back a little, lets say in february or march?

Any other hints or information any of you have that might help in this project, please feel free to contribute.

Thanks.

Jim

 

[gatorlady]

I can tell you what I know from exp. I had harvested llive oak acorns and potted them in 4" containers. They did fairly well with about 80% coming out. I don't think that by spring you will have any problems with root growth, as in the 4"ers when they got up in size, the roots wound around inside the pots. A year or so later when it was time to pot them into gallon pots, the roots that had come out of the smaller pot bottoms and grown into the ground were somewhat and only slightly damaged getting them out of the pots, but nothing too serious. As for cutting the tap, I wouldn't. When it's time to bump them up, just be sure to unwind and spread the roots (as I'm sure you knew). Hope this helps.

 

[JimmyT]

thescienceguy, also the acorns need to go through the stratification process for a better germination rate. It's that natural freezing and thawing of seeds during the winter months.click on this link---Stratification (botany) - Wikipedia, the free encyclopedia

 

[thescienceguy]

I can tell you what I know from exp. I had harvested llive oak acorns and potted them in 4" containers. They did fairly well with about 80% coming out. I don't think that by spring you will have any problems with root growth, as in the 4"ers when they got up in size, the roots wound around inside the pots. A year or so later when it was time to pot them into gallon pots, the roots that had come out of the smaller pot bottoms and grown into the ground were somewhat and only slightly damaged getting them out of the pots, but nothing too serious. As for cutting the tap, I wouldn't. When it's time to bump them up, just be sure to unwind and spread the roots (as I'm sure you knew). Hope this helps.

Thanks so much for the practical information. That is what I am looking for.

I think the students are going to conduct this project as an experiment. With the number of acorns we hope to germinate, we can monitor root growth, cut some back if needed, and set aside others as a control.

Jim

 

[thescienceguy]

thescienceguy, also the acorns need to go through the stratification process for a better germination rate. It's that natural freezing and thawing of seeds during the winter months.click on this link---Stratification (botany) - Wikipedia, the free encyclopedia

That is true for most oak.

My research has been:

White oak and Bur oak in particular do not need stratification. In some studies, stratification of White oak acorns actually decreased the germination rate.

White oak and Bur oak acorns can be planted as soon as they fall from the tree. They will begin growing the tap root soon after planting.

White oak and bur oak acorns can be refrigerated to slow the process of germination, but should not be stratified.

Thanks.

Jim

 

[thescienceguy]

I can't figure out why an answer to JimmyT has not been posted. I submitted it more than several hours ago.

I will try again.

JimmyT,

Some of the oaks do not need stratification. White oak and Bur oak in particular will do better without stratification.

They are ready to germinate directly from the tree. One research study I read showed the highest germination rate was when the mature acorns were taken from the tree and soaked in water for a day and then planted.

The acorns can be refrigerated to slow the germination, but this should not be confused with stratification. Eventually, they will germinate even in the refrigerated condition.

Jim

 

[JimmyT]

thescienceguy, I was also reading about a process called scarification that some seeds need to germinate.

 

[burroak]

I did this myself last fall.
First, I planted about 50 burr oak acorns in the fall in a 4'x4' raised bed, using sandy soil taken from a floodplain.

Second, I planted Burr oak in containers in the fall. I placed them in direct sunlight and watered frequently.

Third, I stashed about 100 burr oak acorn in the fridge.

Results:
The burr oaks I planted in the raised bed in the fall came up in the spring very strong, and grew faster than the red oaks I started next to them. I had nearly 100% germination.
The burr oaks I planted in the containers never germinated. I checked some in november, and none had a taproot. None came up in the spring. I had some white oak and chinqapin oak in containers too, and they all had taproots within 2-3 weeks.
The burr oaks I put in the fridge germinated late in the spring, and growth was much slower.

From now on I'm direct seeding them in the fall where I want them to be. Seems like they grow best when you plant them where you want them. If they do indeed germinate in the fall, they do so much later than white oaks and chinqapin oaks.

 

[thescienceguy]

Have some questions for you.

In reference to the acorns you kept in the fridge, did you plant them outside in the spring? They didn't germinate in the fridge during storage?

With reference to the acorns planted outside in the raised bed. Did you replant them, and can you remember the length of the tap root.

I am rethinking the entire project.

I am considering preparing a seed bed for the entire works. Planting them this fall, and then using chicken wire in the spring to protect them until we can dig them up and sell them.

Do you think from your experience that this would work? Can you forsee any problems that I haven't addressed.

Thanks so much Burroak.

Jim

 

[burroak]

Fridge acorns I planted outside in the spring, sometime around April if I remember right. And, no germination in the fridge. I had them mixed with moist leaves/sawdust.

Acrons in the raised bed: Yes, I replanted most of them in June. The tap root varied - longest being about 18 inches if I remember right. I had trouble keeping the tap root intact. I'm pretty sure I broke most of the tips off. This year I plan on placing planting containers inside the raised bed so I can pull them out of the ground without breaking the tap root. I'll probly just use as many 2-liter bottles as I can scrounge up.

And I put chicken wire over the top of the raised bed immediately after I put the acorns in the ground in the fall. The Squirrels LOVE burr oak acorns, and you must protect them!

Last year was my first year doing this, and I plan on doing it again this fall as well, but with a few changes....
This year my raised bed is going to be about 18" high, and using sandy soil taken from a floodplain. I'll be using planting containers (2-liter bottles with holes in the bottoms) to hold the acorns so I can quickly and easily pull them out of the ground for replanting (hopefully without breaking the taproot). Also I won't be doing the refridgerator method for the Burr oaks this year since the growth was delayed and stunted.

Since you will be doing so many, you may want to search for some deep, and thin planting containers. Overall I think you're on the right track. I'm only doing about 30 this year since I just replant them on my property. Although now you have me thinking of selling them.

 

[thescienceguy]

WOW. 18 inch tap root. Resources that I have read have all mentioned the long tap root of the bur oak.

I can forsee a raised bed just for this process. A narrow, two foot high bed with wooden sides. The sides being held in place with stakes that can be knocked out when needed in the spring. To retrieve the seedlings, just take out the sides and dig into the two foot high dirt. Most of the dirt should fall away from the roots and make it easy to retrieve the seedling with out having to dig and break a bunch of roots. You would be taking the seedling out from the side instead of from the top.

I have approximately 1400 acorns. I believe we are thinking more along the lines of planting most of them outside and trying to protect them with fencing and snow to keep them from freezing.

A few I will try to raise over the winter indoors and experiment with ways to maximize their growth rate.

Thanks so much for all the help.

Jim

 

[loamy]

WOW. 18 inch tap root. Resources that I have read have all mentioned the long tap root of the bur oak.

I can forsee a raised bed just for this process. A narrow, two foot high bed with wooden sides. The sides being held in place with stakes that can be knocked out when needed in the spring. To retrieve the seedlings, just take out the sides and dig into the two foot high dirt. Most of the dirt should fall away from the roots and make it easy to retrieve the seedling with out having to dig and break a bunch of roots. You would be taking the seedling out from the side instead of from the top.

I have approximately 1400 acorns. I believe we are thinking more along the lines of planting most of them outside and trying to protect them with fencing and snow to keep them from freezing.

A few I will try to raise over the winter indoors and experiment with ways to maximize their growth rate.

Thanks so much for all the help.

Jim

I would not do a raised bed for roots that go this deep in the first year. To much bed above ground and you risk freezing them. for this amount of acorns, you should just grow them in really deep and wide pots with as many acorns as possible and just submerge it into the ground.
They will be ready for transplanting in the second spring before they come out of dormancy. If you can find pots at-least 12' deep you'll be ok. becauce after all they'll only be in there for one full summer. I once transplanted a 2 year old burr oak, cut the tap-root to 12" And with lots of compost; in my second year after being moved, i'm happy to see 63cm or 25" of new growth.

Goodluck

 

[thescienceguy]

I would not do a raised bed for roots that go this deep in the first year. To much bed above ground and you risk freezing them. for this amount of acorns, you should just grow them in really deep and wide pots with as many acorns as possible and just submerge it into the ground.
They will be ready for transplanting in the second spring before they come out of dormancy. If you can find pots at-least 12' deep you'll be ok. becauce after all they'll only be in there for one full summer. I once transplanted a 2 year old burr oak, cut the tap-root to 12" And with lots of compost; in my second year after being moved, i'm happy to see 63cm or 25" of new growth.

Goodluck

Yup, that idea of a raised bed was kinda' stupid. I realized that soon after posting.

Even though I had a solution in mind, I posed the problem of freezing to my students this morning, and they eventually came up with the same solution I had.

We are going to work up an area and shovel out trenches as deep as we can. Then line them with wide wood boards or salvaged tin. Then back fill around the sides to hold them in place. Then we will fill in the trenches and plant the acorns approximately six inches apart. This way we can dig out along the sides and release the seedlings as gently as possible when the time comes.

This will provide a bed that is level with the surrounding soil, and hopefully keep them from freezing.

This may seem very work intensive, but I have many students that would welcome the alternative to working on assignments in the classroom.

My Environmental Science class is going to try to monitor the soil temperature at various depths throughout the winter and keep a log of the temps.

We are also going to try to raise some indoors, over the winter, by using lights that will be on timers set to mirror the longer growth period of spring and summer. We will gradually increase the photoperiod to approximately 16 hours a day to induce summer growth and see what happens.

Thanks for the information on what you have done. It is very helpful and we appreciate all the help everyone has given us.

Jim