Q & A December 2001
by Michelle Le Strange, UC Master Gardener Advisor

Q.How can I keep my Christmas tree fresh?

A. Each year approximately 33 million real Christmas trees are bought in the United States and enjoyed as the traditional centerpiece of the holiday celebration. The California Christmas Tree Association and the National Safety Council recommend these Christmas tree tips.

When selecting a real tree look for one that is of good green color and not faded. The needles of pines and spruces should bend and not break and should be hard to pull off the branches. On fir species, a needle pulled from a fresh tree will snap when bent, much like a fresh carrot. Also look for a trunk sticky with sap.

At home cut off 1-2 inches of the trunk base to expose pores that are not clogged by sap. The fresh-cut surface should be creamy-white, not yellow or brown. Without a fresh cut, the tree will not be able to absorb water and it will quickly dry out in the home. After the cut is made, put the tree in water as soon as possible. The longer you delay the less ability the tree has to absorb water. Even if a hole is drilled to accommodate a pin-type stand, a fresh cut should also be made on the butt of the trunk.

Place the tree in a sturdy stand, one that will hold at least one gallon of water. An average tree may consume between a quart and a gallon of water per day. If the water level drops below the cut end of the trunk, a seal will form and the tree will stop sucking up the water unless another cut is made. So don't forget to add water every day.

Some reputable sources say to use plain water, while others recommend adding a little sugar to the water by using a can of regular (not diet) lemon-lime soda to maintain tree freshness. A squeeze of real lemon helps keep bacteria from forming in the sugar water. Replenish with soda and lemon regularly.

Place the tree away from heat sources such as heating vents, fireplaces, wood stoves and sunny windows. After Christmas remove the tree before it is completely dead and dried out. Recycle your tree but make sure to unload it at a designated recycling area.

Q. Where is the nation's Christmas tree?

A. In 1926 the giant redwood tree called the General Grant was dedicated as the "Nation's Christmas Tree". It stands 267 feet high with a 33-foot diameter at the base. This massive redwood is 3,500 years old and is located in Kings Canyon National Park in the mountains above the city of Sanger, the Nation's Christmas Tree City.

Q. This fall I planted several beds of bulbs, mostly daffodils, iris, and tulips. Are there any herbicides that are safe to use on them?

A. There are only a few herbicides that can be used to control weeds on newly planted bulbs. Oryzalin (sold as Surflan and Weed Stopper), pendimethalin (sold as Penduluum and Pre-M), Treflan, Team, and XL are all preemergence herbicides (they do not kill established weeds, but do kill germinating weed seedlings). According to their labels they can only be applied 2-4 weeks after planting the bulbs. If weeds have already emerged then lightly cultivate the bulb bed before applying the herbicide. Be sure to irrigate after application. Dacthal and devrinol also carry labels for some bulb situations, but are not as easy to find on store shelves anymore, still many gardeners have not yet exhausted their supply of them.

The only postemergence herbicides that can be used after the bulbs and the weeds have emerged are the grass killers, like as Grass Getter and Grass- Be-Gon. There are no postemergence herbicides specific for broadleaf weeds that won't also hurt the bulb plants.

Q. My peach and nectarine trees have leaf curl. In the spring and early summer many of the leaves were puckered, curled and distorted, and then they all fell off the tree. What should I do?

A. Leaf curl is one of the most common disease problems for backyard gardeners. The good news is that it only affects the leaves and shoots of peaches and nectarines and it is easy to control. The bad news is that if left unchecked for several years, the disease gets progressively worse until fruit production decreases, branches get sunburned, the tree declines and needs to be removed.

To prevent leaf curl, treat peach and nectarine trees with a copper-based fungicide around Thanksgiving after leaves have fallen. A slurry of hydrated lime and copper sulfate (called a Bordeaux mixture) or a synthetic fungicide may be used. Just be sure that the spray compound contains at least 50% copper. If timed properly, a single spray will normally prevent the fungus problem. If it turns out to be a rainy spring a second spray is recommended at bud swell.

December 6, 2001