The Freylinghuysen Arb. HS tree with what appears to be winterburn from the harsh winter of 2002-03. It could also be phomopsis blight. One whole branch died, leaving a hole in the side of the tree's habit. The original top to this specimen was lost some time ago and it is now regrowing a small new leader. It is not producing cones. The foliage is very heavy on this tree. Their sign mislabels it in the "Taxus-Yew Family".

Here is cercospora blight from 2002 as it appears on a newly planted HS early in the spring of 2003. Notice that the new growth is not affected. The diseased branches were pruned away and the tree sprayed. (See the Willowwood tree below. This tree never did well, perhaps due to the poor choice of soil, and was later removed along with the soil.)

Here is another photo of cercospora damage from 2002 as it appeared in the spring of 2003. Note the damage and discoloration on the trunk and branches. Many branches had to be pruned away. The resistance of this tree to cercospora was fairly minimal. Spraying in 2003 prevented any significant reoccurrence.

Here are some diseased branches on the New Jersey Botanical Gardens HS (smaller tree). The extent of the blights was not great, but heat stress on the branch tips (in orange) and cercospora (brown/grey) in the interior were both present. Conditions were worse in 2003 than in 2002, resulting in some foliage loss. By the end of the summer the blighted foliage had dropped away, leaving the tree nearly free of disease.

Here is a photo from Aug. 2003 of cercospora on the species at Reeves-Reed arboretum in Summit NJ. This is when symptoms typically become noticeable. Since 2003 was a wet year the loss of foliage was fairly extensive. The tree is also shaded, leading to sparse foliage.

Here is another photo from Aug. 2003 of cercospora on the species at Reeves-Reed arboretum in Summit NJ. The older, inner foliage gets attacked first. Foliage lower on the tree gets attacked first. Foliage that is simply being shed by the tree will not turn black or grey or have a foul odor when cut.

Here is a photo from Aug. 2003 of what could be phomopsis and/or cercospora on the species at Reeves-Reed arboretum in Summit NJ. Orange needle tips, particularly on new growth, is a typical symptom of phomopsis blight, but this is not generally a serious disease on Sequoia north of the Pennsylvania/Maryland border. One can see in this photo that newer growth tends to be bluer than older needles. Unlike HS, the species has trouble shedding diseased foliage. Summer heat stress owing to high temps and/or lack of soil moisture will result in orange/red inner foliage loss. Yellow foliage can be an indication of overwatering, particularly from manual watering or irrigation as rain rarely causes problems, even with mild flooding.

Here is a close-up of the blight on the Willowwood Arb. HS in Chester NJ as of July/Aug. 2003. Some of the blight appears to be leftover from 2002. A significant portion of the inner foliage was lost and the tree is fairly sparsely foliated. Mostly summer heat stress owing to the orange/red color, though cercospora is in evidence too. This tree should be pruned and sprayed.

It is possible that older HS trees, developed from cuttings are more immune to disease than newer ones developed from grafts.

This may be hard to see, but an unknown stem canker attacks fast growing seedlings generally in Aug. It typically occurs about halfway up the stem, resulting in the lost of the top. The tree needs to be pruned to be saved, resulting in only the lower branches remaining. They have to become the new leader the following year. It may be a form of botrytis.

Botrytis is often associated with the top-lopping stem canker. This disease generally does not attack slow growing seedlings.

Here you can see the effects of shade on seedlings. They grow spindly, with few branches. These seedlings are quite healthy, however. The seedlings to the left, growing in poorer soil, have not developed to anywhere near the same height despite being the same age. Seed starting soil with some slow release fertilizer is recommended. These plants were grown indoors, so their immunity against disease is not known. However, they are unlikely to be killed by botrytis if put outside their second year.

You can also see some of the effect of underwatering on the tall seedlings to the left, which are drooping over from lack of water. They should straighten themselves within an hour of being watered. Even very tiny seedlings will do the same thing. They are relatively drought resistant. It becomes harder to keep them watered as they outgrow the pot, so transplant annually when dormant until they can be put in the ground at 1.5' to 2' in height.

Here you can see the seedlings that grew in tubes as they appeared in Sept. 2003. They are much taller than the ones grown in pots, probably due to their more advanced root systems. They grew most rapidly in Aug. and Sept. The pale one in the back grew very vigorously, but repeated rainstorms eventually overwatered it. The droopiness and yellow color are a good indication of overwatering. The seedling is dying. The others have very good color. Their upright branches, short needles and blue-green color are good indications for disease resistance though most lost a branch or two to botrytis.

Here you can see two seedlings just after germination. The one on the right is normal while the one on the left appears to have a color mutation. It has a golden-yellow stem and green needles compared to the typical red stem and blue-green needles. This type of mutation is something to look out for, since it may be a cultivar in the making.

This seedling was sprayed weekly with fungicide and had all diseased bits removed in the spring. By Oct. 2003 it was still disease free and had doubled in size. It is protected from groundhogs and deer as a precaution. It is a vigorous tree with an above average disease immunity. The foliage is slightly bluer than normal and the tree has a shorter growing season than normal. It was protected from excessive rainfall in 2003 as well.