Fertilizing Young Trees

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bolson32
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Fertilizing Young Trees

Post by bolson32 » October 6th, 2021, 9:26 pm

I saw Morpheus mentioned fertilizing his Thuja Green Giants in another thread and to avoid hijacking I wanted to start a new thread.

I'm trying to establish a shelter belt/ privacy trees across a couple sides of my lot. It's a mixture is spruce, white pine, hybrid poplars, couple birch and some red osier dogwoods.

What's everyone's best fert regimen for young trees? I've seen quite a few differences in opinions, ranging from nothing, to only in the spring. Next summer will be their third season and I haven't had the greatest growth yet, although this last summer was a historically bad drought. Anyway, any tips to help them flourish would be appreciated. Thanks!

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Re: Fertilizing Young Trees

Post by MorpheusPA » October 7th, 2021, 6:26 pm

It really depends on you. Nothing is fine. They don't, technically, need much of anything.

I wasn't waiting on nature to grow my Thuja. I planted in April at 2' tall, then was pretty gentle the first year, feeding at half rate with Miracle Gro (Nature's Poison [tm] according to some detractors; I disagree). Plus the normal organic feeding the lawn got, so May, August, September, and October. They got the same spray of urea the lawn got in November.

Year 2 and onward, the feeding was full strength Miracle Gro every ten days until September (plus organics with the lawn). By year 5, they were hitting 15', so I was backing off the feeding to just the organics the lawn got. Now, year 11, they're about 20', and growth has slowed considerably.

That's fine for Thuja and poplar, but pine, birch and dogwoods just don't need that. Feed in spring after blooming time on the dogwood. Feed in very early fall. That's entirely sufficient. For the pine, you can skip spring if you want.

Water during droughts only, every 2 weeks or so, very deeply, for established trees. Weekly for younger ones, perhaps.

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Re: Fertilizing Young Trees

Post by bolson32 » October 7th, 2021, 9:15 pm

Thanks for the feedback, I was actually thinking miracle gro might be perfect to get past the grass.

I'll pickup a little regimen next spring.

Any merit to the idea that fertilizing trees can cause faster "weak" growth?

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Re: Fertilizing Young Trees

Post by MorpheusPA » October 8th, 2021, 5:35 pm

Some, yes. My Thuja outgrew their capacity to be supported by their root systems and I had to stake them for a year. Those caught up. Thuja don't have much issue translating newer growth to woody growth.

You'll note I didn't recommend heavy synthetic nitrogen for the pine, birch, and dogwood, which would suffer problems with it. Twice a year? Not really a problem. Every ten days? Well...I wouldn't do that. Of them, I'm betting the pine would have the least problem. The birch would be a beacon for insects. The dogwood...hello, anthracnose.

I've done heavy feeding on a magnolia and gotten away with it, but the tree rapidly exceeded genetic specifications. It also blossoms spectacularly in May and regularly but spottily through the season.

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Re: Fertilizing Young Trees

Post by bolson32 » October 8th, 2021, 6:52 pm

Okay, good to know. I'll probably just hit them a couple of times a year then and call it good. I'm currently doing nothing, so I think a couple good dousings with MG would be helpful.

Thank you!


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Re: Fertilizing Young Trees

Post by bolson32 » May 5th, 2022, 4:03 pm

Update: I had Sav-A-Tree come by yesterday to make sure I don't have any glaring disease or insect issues. He seemed to think most of the problems were just due to transplant shock and a bad drought year. He recommended the below things, which I won't actually pay them to do, but I'm wondering if you guys think there's any merit to them.

1: Spray them with horticultural oil to kill off any existing insect problems. He sounded 50:50 on whether this was necessary or not.

2: A few apps of fungicide with some copper spray. I did this last year, but he recommended at least a few sprays every year. I can do this myself, I probably should be.

3: Give them a biostimulant to promote root growth.

Now, the first two, I can easily do myself. Not sure if they're 100% necessary or not but there's not a ton of effort involved and the products are cheap enough.

The last one is probably the one I'm the most curious about. Would a biostimulant help these new young trees establish their root system a little better? I'm just really hoping we've had a bad couple of years and they'll take off now that they've had time to establish, but I'd really like to get these things going this year if I can.

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Re: Fertilizing Young Trees

Post by MorpheusPA » May 5th, 2022, 8:17 pm

1) Meh. If there are bad insects around, sure. But those sprays tend to damage the ecology of the good insects as well. I don't make a habit of using anything unless I'm absolutely certain I need it. Something like a birch might need this as a preventative, though.

2) Again, if required. It depends on the tree. Something like a Thuja should never require it, and if it does, it's occasional and done for. Other trees will differ.

3) Oh, bother, this again. Plants are entirely capable of growing their own roots. That having been said, if you want to spray it down with some Kelp Help from here, bingo, biostimulant, and a good and cheap one. A better method of stimulating root growth is to keep the tree properly watered, fed, and otherwise healthy.
I do find that small amounts of kelp do seem to work wonders in terms of increasing plant size, but there's a fine line between enough and too much. For a tree, that line is probably way above anything you could apply. For a bed of zinnia, it's about 2 ounces per thousand per week. At that point, growth actually slows.

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Re: Fertilizing Young Trees

Post by bolson32 » May 6th, 2022, 10:13 am

Okay, thanks Morph. This is all really helpful.

The reason I had them out is that I have actually been experiencing really high loss rates, nearing 50%, and I wanted to make sure there wasn't something else going on. I've planted well over 1000 trees at my parent's place, granted 90 minutes away, and have well north of 95% success rates. So this just feels odd. He didn't suspect anything crazy from a disease/insect standpoint though, just transplant stress and a couple of bad years. That said, he is an arborist for a for-profit company so he's obviously going to recommend something.

To your last point, If they won't hurt, I'd like to do SOMETHING to get these things going. So if I can hit them with some Kelp Help and a biostimulant a couple of times this year I think I'd really like to. Do you have any recommendations for a good cheap one? Also, when you say to spray it down with some Kelp Help, do you actually apply it foliar? Or would that also just be watered in at the root zone?

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Re: Fertilizing Young Trees

Post by MorpheusPA » May 6th, 2022, 12:23 pm

Huh. I have one spot that has had 100% tree losses. I diagnosed it finally--it was in a runoff area that was unobvious. The ground, during early spring, saturated and drowned the roots, killing the tree. Any tree. Even a lilac couldn't survive it, and those things are bulletproof in Pennsylvania. If the area weren't full 15 hours summer sun and neutral pH, I would have tried a native rhododendron--and that probably would have failed, too.

Most trees fail due to the soil and issues like that. If it's not too wet, it's too dry. Look for issues with drowning roots in spring, fall, or not watering younger trees in summer. Heeling out in winter on new trees can be an issue, too, but that's kind of obvious when the tree falls over.

I've had the best luck (and they're so cheap) with whips and very tiny baby trees raised in pots. They adjust quickly, due to having not much in the way of root systems they need to re-grow (I disapprove on so many levels of ball and burlap that I can't even tell you). Outside of that spot, survival rates of those has been excellent, even though they, on average, don't survive as well due to size. Plus I get to shape the tree from the get-go.

Optimally, keep a young tree slightly damp (like a wrung-out sponge) for its first year. Which is not going to happen, so deeply water it (at least 1" of water) weekly if nature doesn't do that--but mind not to soak the soil, so if it's still wet, don't bother. Let the soil dry to at least an inch down before watering again. You do want the tree to grow roots and stretch out.

There's a Zen koan, "Why does the radish have no roots?" While it's meant as a meditative statement, the accompanying and equally philosophical answer is, "Because rainwater is plentiful." Radishes don't need much in the way of roots. Trees aren't quite the same and will send reasonably suitable anchors, but you still want the roots to develop appropriately.

During the second year, back off a bit on watering. Maybe every 2 weeks, or only if it gets a bit more droughty. And so on. These days, I only water trees if it's a drought. Everybody's established and a minimum of 15 years old.

As per the last point you and I made, it won't hurt to put kelp on them. Foliar spray, absolutely. Ground soak, absolutely. Put your sprayer on and fire away. Figure 4 ounces over the thousand square feet around the tree, divide it down as you wish. It really doesn't take that much.

Kelp Help actually IS a biostimulant. It's loaded with gibberelins, which stimulate root growth, meristem differentiation, and cell growth. If you've seen photos of my gardens, that's why every plant exceeds genetic specifications by 100% or more. The Ageratum are 18" across. The marigold are monstrous. I think I saw bones in the morning glory (I didn't ask questions).

Additionally, if you wished to spread just a bit of alfalfa meal (available as rabbit food at any good pet store), please feel free. It's good for the grass, too. Limit usage to 10 pounds per thousand square feet maximum, twice per year, separated by at least 3 months--more than that actually causes problems and the same paradoxical effect I mentioned above where it does more harm than good. It also stinks like death on a pogo stick when it rots, so overuse is not recommended; amounts recommended will not do this.

I've never tried the two in combination and have no idea how they interact...

Alfalfa is also an extremely gentle feed. I'd add Milorganite to feed them more. Even a synthetic is not a problem when feeding trees.

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Re: Fertilizing Young Trees

Post by bolson32 » May 10th, 2022, 8:18 pm

Thanks Morph. This has been super helpful. I honestly think I'm just going to run drip irrigation to all of them so i can just turn on the faucet once a week. Watering has definitely been a problem, there's ~85 of them across 300ft. Doing that with a hose and buckets is tough.

Do you happen to know if 1/2" Drip irrigation can run that far? Would have a drip spout at each tree and would be about a 600ft run. They sell it in 500ft rolls, so I assume so.

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Re: Fertilizing Young Trees

Post by MorpheusPA » May 11th, 2022, 10:57 am

It depends on your output. I run 1/2" irrigation 100 feet and that's not a problem--limiting output to six gallons a minute. At five hundred feet, you're going to experience a lot of pressure loss at that output, and if your pressure is low, that might be an issue. My pressure's high enough that it's not a problem.

Depending on your setup, twin 300' outputs might be better, but might not be possible (you mentioned they're across 300', so I assume you mean up and back again, you could set them in a U pattern with the hose at the base of the U to limit the length of each run. My back garden has twin branches to limit the length of run as that has to go all the way to the front mailbox and cover 1600 square feet of garden. One heads one way, one the other.

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Re: Fertilizing Young Trees

Post by bolson32 » May 11th, 2022, 1:03 pm

Yea, I think having it all on one run would be problematic. But I should pretty easily be able to just have two and swap the hose after a few hours.

I did a little research on dripdepot.com and it looks like for 1/2" lines they recommend the 200/200 rule. Which is no more than 200gph over 200ft. Since it's longer, I'd definitely need to cut the output. But, I could pretty easily have 2, 300ft runs with 40 drip emitters on them. Do you think 1gph emitters would suffice? Could just run it longer? 40x 2gph might be pushing it per run over 300ft but it might also be just fine. I'm not sure if there's a preferred difference between the output in this use case.

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Re: Fertilizing Young Trees

Post by MorpheusPA » May 12th, 2022, 1:52 pm

1 GPH output is just fine--simply run it longer. I realized that after a while and, in the back garden, now use umbrella sprayers that are much lower in output but spray wider.

It just means that I run the front (450 square feet) for around 15 minutes and it waters deeply. The back needs closer to 45 minutes to cover 1600 square feet.

In your case, with those lengths, you could even drop it to half-gallon drippers spaced closer and run it even longer to even out the pressures. Use self-cleaning drippers and they'll even take care of themselves for the most part.

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Re: Fertilizing Young Trees

Post by bolson32 » May 16th, 2022, 9:34 am

Thanks, Morph! This has been helpful. I'll probably get a couple of lines set up when the spring rains slow down.

I'm sick of fighting the lack of weather and losing so much stock. I should've done this from the get-go. Live and learn I suppose.

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