Quercus terbinella

[NateDav]

Hello everyone,

Last year I collected 2 shrub oak, quercus terbinella, from a nearby ranch in Central Texas. I placed them in a very coarse nursery mix (standard 5 gal can) and placed in semi shade for the year. They survived and put on a bit of growth. I'm considering placing them into a grow box this coming spring, my normal substrate for Mediterranean species is pumice/lava/turface/haydite/pine bark. This is the first time I've worked with quercus species, any recommendations would be appreciated. Thanks in advance.

 

[Leo in N E Illinois]

It is spelled Quercus turbinella, probably an auto-correct error. The shrubby gray live oak.

I had some I raised for a decade from acorns collected outside of Las Vegas. Your Mediterranean substrate should be just fine. A grow box would be fine. You should be able to leave them outdoors without winter protection with no issues. I had trouble being in the cold, Chicago area. I never got much growth out of mine, probably because our summers are relatively cool and relatively short. Can't tell you much more than that.

 

[NateDav]

It is spelled Quercus turbinella, probably an auto-correct error. The shrubby gray live oak.

Yep it's misspelled, wrote this on my android phone. Thanks for noticing . Do you have any other suggestions?

 

[Potawatomi13]

If they only did so so this grow season it would be wise to give one or two years more in present container so roots can grow/regenerate strength lost in collecting. Wait until good vigor is evident. Repot in 2020 might survive but set tree recovery back even more.

 

[Leo in N E Illinois]

Potawatomi is right, oaks do not want to be repotted every year. I would give them another summer in the nursery cans, and this summer try more sun. I still would give them afternoon shade during the hottest part of the summer (when temps are over 95 F). Full sun during the bulk of the growing season. Only give shade during the worst of the heat. The additional growing season without disturbing roots might really help with the recovery.

Your Mediterranean mix sounds fine, but save it for when you move to a different container, maybe 2021 or 2022. Trees really do not like being repotted too often. I often let pines and junipers go as much as 10 years between repotting. Deciduous, if I can, I let them go 3 to 5 years between repotting.

The exceptions are younger trees where you are actively training the nebari. And exceptionally fast growing trees. For example, you might repot a willow tree once a year simply to slow down growth. The root pruning will cause growth to slow and to cause shorter internodes.

 

[rockm]

Soil mix should work. I would be mindful of the watering. Although Texas oaks are relatively drought tolerant, soil in the heat in the summer will dry soil --especially those light on organics--quickly, especially as the trees develop roots to use the water. Deeper training and "final" containers are useful in keeping soil moisture. Stay away from shallow pots--like less than two inches. six to eight inches deep is a ballpark range for them. Bigger the tree, deeper the container.

Establishing a decent root system is the first job with collected oaks. Repotting, as said, is not a yearly thing. It's not even a two year thing. I'd think about every three years with younger trees. I repot my old live oak bonsai about every eight years or so. The more you repot, the slower the top growth. Oaks also develop myc colonies in the roots. Repotting messes that up...

 

[NateDav]

Do you find that they grow better in a more acidic soil medium? Will I need to be using sulfur to create a better environment for fungi? Or should I add more organic to the mix? The pine bark chips usually makes up about 10-15% of the mix, the remainder being equal parts pumice/lava/haydite/turface. Particles are 1/8-1/4".

Oaks are such an interesting species. The adaptations of the leaves their dependency on the rhizosphere, growth habits.

I've been thinking of fertilizers what do you recommend? I was thinking high nitrogen using blood meal and an organic 5-4-6 with humic acid & cal-mag that I make every spring. I want to start using seaweed & kelp extract on my other trees as foliar spray, what are your thoughts about their use on Oaks? Any experience with using the extracts?

I have these large Italian terra cotta bulb containers 12" and a 14" about 4.5 inches deep. I was don't tho slip pot them and add my substrate trying not to disturb the roots much. But like suggested I probably leave them in those cursed cans .

I like to plan ahead. Thanks for the insights everyone.

 

[rockm]

Do you find that they grow better in a more acidic soil medium? Will I need to be using sulfur to create a better environment for fungi? Or should I add more organic to the mix? The pine bark chips usually makes up about 10-15% of the mix, the remainder being equal parts pumice/lava/haydite/turface. Particles are 1/8-1/4".

Oaks are such an interesting species. The adaptations of the leaves their dependency on the rhizosphere, growth habits.

I've been thinking of fertilizers what do you recommend? I was thinking high nitrogen using blood meal and an organic 5-4-6 with humic acid & cal-mag that I make every spring. I want to start using seaweed & kelp extract on my other trees as foliar spray, what are your thoughts about their use on Oaks? Any experience with using the extracts?

I have these large Italian terra cotta bulb containers 12" and a 14" about 4.5 inches deep. I was don't tho slip pot them and add my substrate trying not to disturb the roots much. But like suggested I probably leave them in those cursed cans .

I like to plan ahead. Thanks for the insights everyone.

I just use plain old bonsai soil, haydite, hort sand, a bit of pumice and sifted bark (30 % or so) for my oaks. I don't worry about soil pH levels all that much. I feed them regular ferts like Miracle Grow, along with organic-based ferts like Bio-Gold both at once. Bio Gold goes on the soil surface, I use liquid fert once a week full strength. Iv'e tried the blood/bone meal/seaweed etc route. Didn't produce much in the way of results. the extract thing is marketing...mostly, driven by the nursery industry. It can work, but it doesn't work all that dramatically and its expensive.

I think trying to encourage myc typically does the opposite. Wait and it will show up on its own.

 

[Leo in N E Illinois]

About "Slip Potting" this concept is bullshit, in that there is no such thing as a "gentle repot". Disturbing the roots of a tree is always traumatic, no matter how "gentle" you may think you are. Any flexing of the root ball will break fine feeder roots. Vibrations will break more. The mycorrhiza are getting disrupted. Every Slip potting is just as bad as a full repot. You would be better served to do a real repot, and all the associated root work, that way there is no confusion about the amount of time the tree needs to recover.

If you leave the root ball intact, you have the additional problem of 2 different types of potting medium in the same pot. This wildly complicates watering. The old mix will dry out more slowly, the new mix will tend to be dry. If you keep the pot wet enough to get roots to move to the new mix, you risk starting a rot in the older, wetter mix. It can quickly become a nightmare. It is always best to do a full repot or otherwise don't touch the roots.

Besides, every time I try to "slip pot" something, the root ball falls apart and I have a full repot going anyway.

So when it comes to bonsai and tree care - loose the words "slip potting" from your vocabulary. With sensitive trees, like JWP it can really matter. A slip potting counts as repotting. If you are only repotting once every 3 years, this can stick you with real problems.

 

[Leo in N E Illinois]

I largely agree with RockM, about soil pH and fertilizing. Your nursery pot mix is what? mostly pine bark? Pine bark and fir bark automatically create a moderately acidic soil and if in quantities around 30% of the mix or more, will have the buffer capacity to counteract medium hardness irrigation water that you would use during summer droughts. No need to add sulfur unless you are using extremely hard water for your irrigation water or you are growing some true calcifuge plants like carnivorous plants. High bush blueberries are borderline, I do use sulfur for blueberries, but they need more acidic soils than azalea.

Oaks are widespread, occurring in a range of soils, while they like an acidic soil they are capable of adapting to a pretty wide range.

So in general, keep it simple, as RockM suggested.

On fertilizer, if you are "serious fanatic" about going all organic and keeping mycorrhiza happy, be sure to supplement humic and fulvic acids, and keep nitrate fertilizer solutions dilute. By dilute I mean for most nitrate fertilizers use no more than 40 ppm. This works out to about 1/4 teaspoon per gallon for a 10-10-10 fertilizer. I use a 13-1-4 fertilizer at this rate. Too much typing to give all the why of the 13-1-4, I'll save that for another time. Key is dilute will be less disruptive to the mycorrhiza. I do fertilize more frequently. In rapid growth I will fertilize with every watering. Rain provides clear water flushes between fertilizer applications. I do get weekly or more frequent rain except for a short period in summer where rain might be 14 days between showers.

One experiment I am observing, they cut out use of nitrates entirely, using primarily amino acids, and composted manures as the nitrogen sources. This seems less disruptive to mycorrhiza, my friend actually had bolete mushroom fruit in one of his pines. Bolete are one of the mycorrhizal mushrooms.

In general, if you have a good simple mix, as suggested in this thread, with a bark component, you will get healthy roots. Keep it simple, don't worry. Mycorrhiza will appear.

 

[Potawatomi13]

Personally have never worried about or checked PH or mic on the roots. Just do necessary management of any tap roots at repot and other shortening, replace with about 60-70% pumice and 30% organic and water with tap water. Fertilize weekly during growth season with 20-20-20 garden center fertilizer. All do great.

 

[NateDav]

Sounds like a heavier organic component in the mix will be in order. I'll double the amount of PB aggregate. If I leave them in the cans for another year can I safely bare root them to remove all the clay? Or is it better to treat like a field pine and remove over successive repottings?

 

[Potawatomi13]

Personally have gotten two bare root Oaks and others substrate basically fell off roots and all survived with good care. "However" would suggest if truly clay substrate on roots do this carefullyas possible to preserve small roots. Also if taproots not already shortened may need to do over multi repots little at a time depending on roots left above cut.

 

[NateDav]

Excellent information, thank you.

 

[Leo in N E Illinois]

I have bare rooted young oaks. No problem.