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Sick Giant Sequoias

Posted by chrispon 9b (My Page) on
Thu, Jul 3, 14 at 10:23

I'm Christos from Greece and I've got two 15 inches tall Giant Sequoias planted in 5 liter pots,I bought them last December and they were about 5 inches tall. So far they were doing great, but one month ago they don't look very healthy. I discovered a few weak and brown colored branches and needles. Note that i allow the soil to barely dry between waterings, temperatures in my area this time of the year reach around 30 - 35 degrees celcius during the day. Is there any fertilizer of specific content you could recommend and when is the best time to transplant them to the ground or a larger pot? I asked for advice from a U.S nursery specializing in Sequoia trees and they said it might be just a blemish, they also suggested using a fungicide effective against botrytis fungus. I thought i ask for a second opinion. I've already sprayed the one sequoia with a fungicide against botrytis cinerea and applied a small dose of iron (Fe) on both of them and removed the affected branches. I also bought a conifer fertilizer 9+6+11 with Magnesium, would that do or should i go for the 20+20+20 i read somewhere? What should i do?
This photo was taken a month ago, now it looks worst.

Follow-Up Postings:

RE: Sick Giant Sequoias

One more photo taken a month ago.

RE: Sick Giant Sequoias

Trees, and conifers in particular, don't like to live in pots, instead preferring to be planted in the ground under full sunlight. I expect Giant Sequioas will do well in Greece, given that they are native to a Mediterranean climate. The best time to plant them in the ground is October, so that there is no risk of them drying out in the heat and so that they have all winter and spring to spread their roots out before next summer's heat and drought come. So I would wait until October to plant them in the ground.

It sounds like you are doing the right thing letting the soil dry slightly out before watering again. About how many days do they go without water? I would not wait more than 3 days between waterings. When you water them, do so *thoroughly* (ie. until you see some water leaking from the bottom of the container). Regarding fertilizers - fertilizer salt mixtures are dangerous because they can burn roots and can cause osmotic stress, which is worst in the summer. I would not use them. Instead, I would make a very dilute seaweed extract solution or nothing at all.

RE: Sick Giant Sequoias

Giant sequoia are actually native to the Sierra Nevada Mountains in California, between about 4-7,000 ft, with virtually no maritime influence. They are under snow for most of the winter, although they are accustomed to a dry summer.

I can grow S. giganteum cultivars here in a true Mediterranean climate but I do irrigate them year-round and they would prefer to be in a place with cooler summers.

This is just fyi to help you understand what they are accustomed to the wild.


RE: Sick Giant Sequoias

Guys I'm confused! I know that Giant Sequoia prefer high altitude but i don't think that my location is affected by the sea.
Is there a chance the roots might be affected by some kind of fungus because the fungicide against botrytis cinerea i used it doesn't seem to work.
So you don't recommend fertilizers?!


RE: Sick Giant Sequoias

Giant Sequioas are hardy enough to grow on well-drained, rocky slopes with absolutely no rain for 6 months out of the year. They'll do just fine no matter where you are in Greece, and they don't need to be babied with irrigation beyond the first year in the ground. Sure they'll grow faster at higher elevations (Mount Parnitha seems to be in need of some trees) but they'll live just fine even at sea level.

It's possible that the roots are affected by fungi - pots don't allow good oxygenation, and while you may think the soil is dry on top, it may be constantly boggy at the bottom, creating a conducive environment for fungi. If you're worried that the tree won't survive until October, then go ahead and plant it in the ground now, and water it thoroughly every day until the winter.

If you want to keep the plant in a pot, the only fertilizer I would use is Seaweed extract, which will provide any micronutrients it needs without burning the roots.

This post was edited by bluecone on Mon, Jul 7, 14 at 13:05

RE: Sick Giant Sequoias

If the roots are affected by fungus is there any chance to survive?

RE: Sick Giant Sequoias

Of course it can survive!

First of all, I don't think you can assume that the tree's symptoms are due to a pathogenic fungus. A few yellowing branches in a potted tree could be simply due to lack of root oxygenation, nutrient deficiency, too much shade, too much/too little water, etc. Most of these factors are eliminated by planting the tree in the ground in full sun and then thoroughly watering it every day for 1 year during the warm and dry seasons. If the tree is looking worse and worse while in the pot, just plant it in the ground, and it will have every chance of perking up.

Also, conifers love symbiotic mycorrhizal fungi, which help their roots extract nutrients more efficiently from the soil. This is why I wouldn't advise adding anti-fungals on the roots. Check out the following article:

Here is a link that might be useful: Conifers and beneficial mycorrhizal fungi

RE: Sick Giant Sequoias

Hi Christos,
Let me tell you about the fungus which is slowly killing the few Giant Sequoias in Eastern US. This is Cercospora sequoiae. This is not a root fungus, it starts on the branch tips. The plants become so ugly and deformed that they will be removed. This can happen to young trees and old trees. I don't know the solution, I've given up.

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