GARDENING: Ordinary blueberry plant may struggle in local climate

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Question: My four year-old blueberry plant leafed out in December. Now it has burst forth in buds. It has not done this before. What's up?

Answer: Do you know if this is a low chill blueberry or not? What is the variety?

Blueberry is going to have several strikes against it right from the start in this climate. First is the acidic soil it requires. You may have to use quite a bit of compost and organic mulch plus some acidifying agent for the soil. Sulfur is very slow to work unless you use very finely ground sulfur or a type that you can slurry with water. It is still slow to work unless the soil is warm. Aluminum sulfate may be a better choice.

Second is the chilling that is required for good fruiting. There are low chill blueberries available that would be better suited to our climate and may have a better chance here. You may get some fruit if it is not a low chill type, or sporadically over the years if you can keep it in good health.

Flower bud formation and development, as with most perennial fruit crops, occurs in the late summer and fall as the length of the day shortens. For horticulture techies it is really the longer night rather than the shorter days. All buds when first developing are leaf buds but depending on the day length and temperature they either convert to flower buds or stay as leaf buds.

High temperatures usually will keep leaf buds from converting to flower buds to some degree. You can tell if you have flower buds or not. As flower buds develop they will be larger and rounder than leaf buds, and you should be able to distinguish the difference right about now. They should be on this past year's growth.

As far as leafing out and swollen buds, early producing peaches and some other stone fruit are leafing out right now and flower buds are swollen. So to see swollen buds is not unusual right now. If you look around at the trees in town you will see many trees with swollen buds. They will stay this way until the temperatures warm up. This is going to be a problem if temperatures reach freezing and below now that buds are swollen.

There is nothing you can do about it but wait and see what happens. If they do begin to leaf and flower early you might consider moving them to a colder part of the yard where there is less reflected heat and light from walls and buildings.

Q: I would like some information on when should I pick my lemons and when should I prune the lemon tree, if at all.

A: You didn't mention which lemon you have. If it is Meyer's then it is not a true lemon. It is a cross between a true lemon and another citrus.

Meyer's lemon will get much sweeter than a true lemon. They mature at different times than some other true lemons but can be used just like a lemon.

When picking lemons you have choices. You can pick them when they are fully mature, which can be progressively over a period of time. At full maturity, the fruit will turn yellow on the tree. In the maturing process, whether on the tree or off of the tree, the rind thins and the pulp increase in juiciness.

You can pick them when they begin their ripening process, turning light green and before they are yellow. In this case you can let them mature -- ripen or cure -- for several days to a couple of weeks off the tree, and the rind will thin and the pulp will juice up after picking.

Or, they can be picked when they reach the size you want regardless of their maturity and let them mature off of the tree. Commercial growers usually pick them this way. They pick when the fruit reaches no more than 2 1/2 inches in diameter and the juice content is 25 percent. This standardizes them for the mass markets. They continue to cure during shipment.

When harvesting lemons, don't just pull the fruit off the branch unless you plan on using the fruit soon. This will leave a hole in the stem end that allows rotting fungi and bacteria to enter and may cause it to rot early and prevent any long term keeping. Snip the stem connecting the fruit to the tree. Remember that lemons bruise easily and try not to damage the rind when picking or it affects the quality of the rind.

Not much pruning is necessary for citrus. You can shape lemon trees any way you want for looks but be sure to remove the dead, crossing limbs and enough wood to leave space for the fruit to grow and some penetration of light into the tree canopy. You can do that as soon as you pick or actually any time.

Q: I'm starting my tomatoes from seed and have been for years. How do I "force" the seedlings to come up with thick healthy stems like the plants in nurseries? When they come up they seem to "shoot" straight up overnight with a stem that is needle thin and almost transparent. Should I cut the top of the plants to get healthier, thicker plants?

A: Don't cut the top of the plants off. This will kill the plants if they are seedlings. We call this type of growth "legginess" or "stretching." The primary reasons are not enough light, too warm temperatures and excess fertilizer. There are interactions between all of these and proper manipulation of them in relation to each other will give you the "stocky" plants that you want. The stocky plants will be healthier and more capable of withstanding the shock of being planted outdoors.

Let me explain the right environment for them and then we can explore options available to you. The perfect environment would be warm germinating temperatures for the seeds until they are up, and then the application of warm days and cool nights. Light is not important for them to germinate so any warm spot will work. Once they show any signs of germination, however, they have to be put under lights or given enough sunlight to prevent plant stretch.

Enough light would mean either high light intensities for at least 8 to 10 hours a day, or if you can't give them enough intensity, longer periods with lower light levels such as 12 to 15 hours a day. You have to lower the nighttime temperatures when the light is not on to prevent stretching. If you have lower light levels then you must lower daytime and nighttime growing temperatures and decrease fertilizer applications.

Higher light intensities and longer durations mean you can grow them under warmer temperatures and give them more fertilizer. This also would mean you will have transplants ready sooner. Less light, cooler temperatures and less fertilizer will delay the time they will be ready as transplants.

So to review: lower light levels means lower temperatures and less fertilizer. Higher light levels such as direct sunlight means you can have higher temperatures and give more fertilizer. You must lower the nighttime temperatures regardless.

Plain old fluorescent lights will work for seedlings. However, the lights must be within a few inches of the seedlings when they are germinating and as they are growing. As the seedlings grow, you raise the lights so they remain just a few inches above the plants. The lights can be put on a timer to give 12 to 14 hours of light a day. Nighttime temperatures should drop to at least the low 60s but no lower than about 50 F to prevent chilling damage of the seedlings.

That's textbook. However, I have grown some varieties as transplants at nighttime temperatures in the 40s with success. However, it is still recommended to avoid that if possible.

Day time temperatures should be between 75 and 85 F as long as light is available to the plant. Fertilize lightly about every two weeks with the irrigation water or use a high quality compost in the soil mix and you will not need any more applications of fertilizer until they are planted.

I have had good luck in this climate starting tomato transplants in the garden area where they will be grown by preparing the soil ahead of time with compost, warming the soil with clear plastic and sunlight for about one week, cutting a slit in the plastic, and direct seeding into the soil through the slit in the plastic. I have done this in mid-January and uncovered them when all danger of frost has passed and nighttime temperatures are in the 40s. I have even left the plastic on the rows much longer than that with good luck as well. They establish very quickly in this manner.

Bob Morris is a horticulture specialist with the University of Nevada Cooperative Extension.