Saffron crocus loves valley's climate, soil

My last class in February will be on how to grow lawns here in our climate. It will be at Plant World Nursery at noon Sunday. You can sign up by emailing me at or online at

Q: I live in Summerlin and I want to grow saffron crocus. Is our area suitable for the successful propagation of this plant? If so, can you tell me the best source for the sativus corms? I would like to plant in the early spring if possible.

A: Yes, saffron will grow here and does quite well. Saffron, a type of crocus, is in the iris family, is one of the most expensive spices in the world. It takes about 60,000 crocus flowers to make one pound of saffron. One of our volunteers began growing it successfully at the University of Nevada Cooperative Extension Master Gardener Orchard in North Las Vegas a couple of years ago.

There is no seed so propagation is by planting the bulb, which is actually a corm much like a tulip bulb. Your best source for corms for planting will be online. Saffron crocus loves our alkaline desert soils, hot dry climate and mild winters. It does well in climates and soils that can grow pistachios.

Saffron bulbs should be planted in full sun in heavily composted desert soil along with additions of your favorite phosphorus fertilizer. Planting should be about 4 inches deep and about 4 inches apart. They should be irrigated and mulched with light mulch, such as straw. Lightly fertilize continuously through the season to increase bulb size so it can be further propagated.

There are different levels of quality in saffron, usually based on its color and taste. You can affect the quality of saffron by manipulating how it is grown. Grow it so it is "happy" and it will produce a good quality product.

Q: I would like to plant some trees in containers until I can plant them in my yard in a few years. Can they stay in containers if I'm careful with them? I'm thinking about apricot, pluot, orange and maybe a pomegranate.

A: If you have purchased these in containers, you will probably not want to keep them in the same container more than perhaps that single growing season if you plan to plant them in the yard. Generally speaking, if you plan to replant them, then they should be moved into progressively larger containers or the roots will be permanently damaged. Eventually, the containers you'll need will have to be large, whiskey barrel-sized or larger.

Once these trees start to get bigger they will be more difficult to transplant into the yard. This just means they are more likely to suffer from transplant shock and recover from this shock more slowly when moved. I would recommend that if you want fruit trees in containers, then keep them in the container permanently. When you are ready to plant in the yard, then purchase trees specifically for the yard.

Of the group you mention, citrus is probably the best choice for a container. Try to locate a citrus on a dwarfing type of trifoliate orange rootstock. Trifoliate orange rootstock is very cold tolerant, which you will need in our climate unless you can protect the plant from freezing temperatures. There are a few selections of trifoliate orange rootstock that are more dwarfing than others. Focus on these if you can find them.

My next choice for a container might be one of the smaller pomegranates, such as the variety Sweet, which would be a better choice for containers as opposed to Wonderful. The fruit is excellent, as good as or better than Wonderful.

If you select an apricot, then I would pick one of the miniatures such as Pixie-Cot or a standard-sized tree such as Gold Kist, which tends to stay smaller when on Nemaguard rootstock at least.

Among the pluots for a container I would probably pick Flavor King, which stays naturally smaller than some of the other pluots. It, however, will need a pollenizer tree such as Santa Rosa plum.

If you keep them in containers, don't expect these trees to be long lived. I hope this helps.

Q: Why does one of my pine trees seem so sparse and inadequate? I purchased four Mondale pines and treat them all equally. But one of them looks so scrawny. The others look healthy and appear to be robust. Any thoughts on that?

A: The usual reason for a pine tree being sparse and not full is that it is not receiving the same treatment as the others. Pine trees generally maintain needles on their branches until the wood gets to be 3 to 5 years old and then the needles are dropped from the older wood. This older branch has no needles except on small branches growing from it that are less than 5 years old.

The reason for canopy thinning is the loss of needles at a higher rate than they are being replaced. So the bottom line for a pine tree becoming sparse is that the tree is not putting on enough new growth. Reasons for this include a lack of water, fertilizer, damage to the tree or, less likely, diseases or insects.

By far the most common reason is that the amount of applied water is not enough. So when you say you treat them the same, it does not necessarily mean these treatments are all reaching the trees equally. But if there is inadequate water, two things will happen: The tree will put on less growth and the needles will begin dying back from the tips.

The first thing to do is to check and make sure that whatever is delivering water to the tree is not plugged. Secondly, make sure that water is not running off the surface to some other location. Just because water is applied to a tree does not mean it is getting to the roots.

Remember, that as trees get bigger their demand for water increases. The increase is not simply a few gallons per year, but is much greater because trees are three dimensional in their water use. Unlike a lawn, when a tree doubles in size its need for water more than doubles.

The next most common reason is that the roots of the tree never fully established into the surrounding soil after planting. This can be because the tree was too old for the container and the roots started circling .

It also can be because the tree was not firmly staked at the time of planting. Correctly staking a tree will immobilize the roots and help them grow successfully into the surrounding soil. You should be able to push on the trunk and not see any soil movement at the base of the trunk.

The next most common reason is damage to the roots or trunk. This will be far less likely than a watering problem but much easier to identify. This can be physical damage like construction, damage from chemicals like salts or weed killers, insect or diseases like collar rot.

If the tree is being shaded by other plants and not receiving enough light (at least six hours a day), then the branches in the shade can drop their needles. If this is the case, then some pruning to allow more light will help.

Bob Morris is a horticulture expert living in Las Vegas. Visit his blog at