Container gardening presents many challenges

Apricots are coming out of their ears at the University of Nevada Cooperative Extension Master Gardeners Orchard in North Las Vegas and the peaches are starting to come in. Some of the best peaches are the early ones. Specialty garlic is ready now as well. It is not a pick-your-own but fruit is harvested for you and very reasonably priced. Come on out any Saturday or Tuesday morning before noon. Call the master gardener help line at 257-5555 for directions.

Q: I am a new gardener. I am growing everything in pots including my fruit trees: figs, cherries and peaches, which are all on dwarf root stocks. The trees are in 30-inch pots holding 6 cubic feet of soil. My tomatoes, eggplant, peppers, squash and others I grow are in 5-gallon buckets.

I am growing 12 different varieties of raspberries and blackberries in 20-gallon containers with a trellis on each pot. I started my garden a bit late so it is mostly in the shade. I am thinking about taking it out into the sunlight after the summer to stimulate more fruiting on the plants.

A: You have to be a good gardener to pull that off. Container gardening can be quite a challenge, but if you have no other alternative then it is what it is. Containers are not very forgiving. Even with 6 cubic feet there is not much room for error so they require more monitoring than plants grown in the ground.

Irrigation, soil temperatures due to the overheating of the container and soil nutrients because the soil can be exhausted fairly quickly, all are going to require careful monitoring. With smaller containers, you can dump the soil and start fresh again. Small containers overheat in the summer very easily and the soil temperatures, which can damage the roots of plants, can be a problem.

Putting them in the shade helps, but finding the right balance of sunlight and shade can be tricky. Flowering and fruiting plants require more sunlight than plants grown for just their leaves. The fertilizer requirement for leafy plants is different than flowering plants.

Leafy plants require more nitrogen while the flowering and fruiting plants require a more favorable balance between nitrogen and phosphorus. And don't forget to rotate plants that are annuals so you don't build up disease and insect problems in the container soils. If growing in containers does not work out for you, try growing them in the ground. I can help you get started with that. Just let me know, but don't give up!

Q: I have a question regarding our pomegranate trees. Two years ago, we had an abundance of good-sized pomegranates from two trees. These trees are about 25 feet apart. However, last year we only got about six total from both trees.

This year there is an abundance of blooms and many already have a fruit set. It looks like there will be at least 25 to 30 pomegranates on each tree. Should I thin some of the fruits after they have set? Is there a reason why one year we get an abundance of fruit and the next virtually none?

A: You didn't tell me if last year you had an abundance of blooms as well as no fruit, or if you had few flowers and also few fruit. Of course, if you didn't have many flowers, then you would not have many fruit either.

In this case, it sounds like the growth went into shoot and leaf growth rather than flower production. If plants are in a very juvenile stage, they tend to put their energy into gaining size. As they get older and they mature, they will begin to produce more fruit.

If you prune pomegranates so that you remove excessive new growth but keep the older, larger wood, you will produce fewer fruit but they will be larger. I only remove pomegranate fruit when they are small if they are directly opposite each other. If there is at least an inch or two between the fruit, I leave them both on.

I will post some pictures on my blog at Xtremehorticulture of the Desert to show you what I am talking about.

Q: My property is in the shape of a pizza slice so I have tons of room in my backyard. I have a dwarf peach tree, Utah Sweet pomegranate, Valencia orange, Thompson seedless grape and Flame seedless grape. The past couple of years I have been using a drip system along with all my other backyard foliage. I used to water once per week for an hour during the winter, three times per week for an hour each during the spring and fall, and an hour per day during the summer. My fruit production was OK, nothing special. I have now switched from drip to watering with a hose.

Do you have any suggestions for watering my fruit trees? I'm also planning on giving cantaloupe a try. Do you have any tips or suggestions? I have also found that my Thompson seedless grapes have been turning brown and some of the leaves have been curling in. I attached pictures of both issues. What do you think could be my problem? - Justice Fisher

A: This seems to be the year for grape problems. Grapes do wonderfully well in our climate as long as the soil is prepared well at the time of planting, they get adequate amounts of water frequently enough and you cover the soil surface with organic mulch.

Some people believe grapes should struggle to produce a quality crop of grapes. Believe me, in our climate and in our soils they struggle enough without imposing additional struggles. To get good grapes, keep them healthy .

We did have some strong winds earlier that can cause the kind of damage you mentioned and that appears in the picture you sent to me. Watch the new foliage as it emerges. If it looks healthy, don't worry about the older foliage. That is old damage that was just temporary.

You talk about watering for a certain length of time. This is like me asking you how many minutes of coffee or tea you drink. Or, if you don't drink coffee or tea, whatever beverage is your favorite. We don't talk about minutes or hours when we talk about drinking something. Likewise, when we give plants a "drink of water" we should not be talking about time but instead the volume of water we apply.

I don't know how many drip emitters you have and I don't know how much water each one delivers in an hour. So I am going to guess you have four emitters for each tree and they deliver 4 gallons of water in an hour. This would mean that in one hour these trees would receive 16 gallons. For a medium-size tree, this is far too little.

When watering with a drip system it should run for a long period of time, in some cases two or three hours. You will double the amount of water to these trees if you increase your watering from one hour to two hours. I would try this first.

Drip irrigation is extremely accurate in applying the water, much more accurate, efficient and consistent than using a hose.

Bob Morris is a horticulture expert living in Las Vegas; he is on special assignment in the Balkh Province, Afghanistan, for the University of California, Davis. Visit his blog at xtremehorticulture.blogspot.com.