I'm late to this but I thought I'd add some advice. I have a small grove of about 24 trees (Hass, Fuerte and Zutano) in Southern California. Leaf tips turning brown is usually a sign of water problems. When the soil dries out, it leaches salt from the ground (which is bad) and causes the tip burn. If you have spots on the leaves, that's usually a pest like a persea mite. My trees are in Sandy Loam soil. You can tell if they need water by clumping the soil in your hand. If it drips water when you squeeze it, it's too wet. Soil that is too wet will lead to root rot. If it doesn't hold a shape from your fingers when you squeeze it, it's too dry and they'll leach salts from the ground. It should hold the shape from your fingers. They like a lot of water but they don't like sitting in water. It has to drain away. That's why most avocado groves are on hillsides. If you don't have hilly land, build a mound and plant the tree in the middle of it so the water can drain off. They like full sun but they have to be protected from sunburn when they're young if it gets really hot where you are. If the trunk or branches are turning black, they may be getting sunburned. To protect it, mix 1/2 white indoor latex paint and 1/2 water (whitewash) and paint the trunk and any exposed branches with it. Once you get a nice canopy, you can stop painting the trunk. Usually once per year is all that is necessary. Don't let the canopy touch the ground. Keep the canopy trimmed about 2 feet off the ground. My trees usually get two waterings per week in the summer when it's hot and sunny, one short and one long. If I get rain of 1/2" or more, I don't water for about a week. In the winter, when it rains here, I may not need to water at all. They usually don't like pots either. Their roots are shallow and spread out to the canopy of the tree. They can tolerate cold down to about 27F. If you get frost or snow, it will kill the tree. They also like a soil ph of 6 to 6.5. It's normal for leaves to fall in the winter. Leave them around the tree and don't let grass or weeds near them. Resist the temptation to clean up the leaves. They help protect the roots and help keep the soil from drying out too quickly. The licorice smell from a torn leaf is usually the sign of a tree that won't grow avocados. It should have a fresh green smell. Growing from a pit will usually not produce avocados and if it does, it's going to take about 10 to 15 years to produce, and even then, they may not produce good tasting fruit. Most growers buy grafted trees or graft themselves from a verified tree that produces good fruit.

I might not plant evergreen dogwoods in sun in a hot climate. Otherwise the soil conditions could be involved. I've seen brown tips on evergreen dogwoods here as well. They are often not the most thrifty and handsome of trees. Species delimitation within this subgenus is controversial. Over 15 new taxa have been published since the 1950s. This treatment follows Xiang (Bull. Bot. Res., Harbin 7(2): 33�"52. 1987), who recognized 13 subspecies among four species, i.e., Cornus capitata, C. hongkongensis, C. kousa, and C. multinervosa. However, a preliminary allozyme investigation by Dudley and Santamour (Phytologia 77: 425�"430. 1995) suggested that C. capitata subsp. capitata is quite divergent from C. capitata subsp. angustata. Thus, in the present treatment, we recognize C. elliptica as a species separate from C. capitata. Further studies are needed to test the various species delimitations in the group Here is a link that might be useful: 5. Cornus subg. Syncarpea (Nakai) Q. Y. Xiang, Acta Phytotax. Sin. 25: 128. 1987. This post was edited by bboy on Thu, May 9, 13 at 0:13

Yes I agree with GH I have a few the same as yours growing here that I didn't look after too well, while we were building the house and had the same trouble, now with all that behind us and I water regular they are coming on great..... Cheers..MM.

is that snow out the window if it is then the plant is cold and need more light , get a grow light for it and don't give it a lot of water make sure the soil is dry first , best of luck to you .