Plants need fertilizer regularly to grow, produce

Earlier in the season, around mid-March, I was encouraging you to plant your own onion transplants and grow your own onions. They are so much better tasting than store-bought onions. I gave the readers here and on my blog some varieties to choose from; many are available from seed, which should be started in about mid-October, the same time as you would plant garlic.

Most people forget an important concept in their home gardens — regular fertilizing. As plants get bigger or start producing they are taking all of these “goodies” from the soil to get bigger or start producing.

What would happen to you if you were always giving and receiving nothing in return? Plants can’t continue to “give” without getting something in return if you expect them to be healthy and productive. So all plants, as they get bigger and you harvest from them, require fertilizer.

Fertilize your garden plants monthly when they are producing. Think about what they are taking from the soil. Is the soil enriched so they have plenty to pick from or is the soil’s nutrient reserve running low?

The first nutrient to disappear from the soil, for a number of reasons, is nitrogen. It is very important to supplement your vegetables with some nitrogen monthly.

If the plants are growing, it is not wise to just broadcast the fertilizer (throw it out over the garden willy-nilly) or the fertilizer salts may burn foliage. Deposit the dry fertilizer next to each plant or dribble it along the row. This is called side-dressing with nitrogen.

Why did I mention onions earlier? Because they need to be side-dressed as well and are frequently forgotten. Onions and garlic need one more side-dressing, then you should stop as you will be harvesting them in two months.

Use your favorite source of nitrogen. If you are an organic gardener, select an organic form that you like. If you are not that fussy, then use a traditional ag-type nitrogen fertilizer such as ammonium sulfate. When you side-dress, it is normally just nitrogen as it moves into the soil freely with an irrigation.

What makes big onions? The variety you select, improved garden soil, spacing them 4 to 6 inches apart, regular and frequent watering, weed control and side-dressing with nitrogen as they are growing and expanding. Pull or lift them when the tops fall over naturally. If you are pulling them, make sure the soil is wet when you are pulling or you will pull the tops off.

Remember, my blog, Xtremehorticulture of the Desert, has a lot of pictures that supplement my discussions here.

Q: I was wondering whether you could point me in the right direction. I had been using a great liquid fertilizer that I was able to obtain from the 99 cents store in Henderson. It has discontinued the product and I can’t seem to find it anywhere. I have succulent plants and cactuses on my patio and the liquid fertilizer really seemed to help. Could you suggest where I might obtain the liquid fertilizer or suggest some other product for my plants?

A: I know you probably got a pretty good deal with that fertilizer and that may not happen again for a while but there are some good liquid fertilizers out there. Sounds like you are into the bargain bins when you buy things so you may not like my suggestions.

Good fertilizers are nearly never inexpensive. One of the best ones you could use would be to make your own compost tea using high-quality compost. I can’t compare all the products out there available in Las Vegas but one that I know about is Happy Frog compost. Be careful when using it because it has had fungus gnats in it still working the compost so don’t use it inside the house. It is fine for making tea or using outside (our desert heat will kill the gnats).

You take about two handfuls of this compost and put it in about a gallon of warm water and let it soak overnight. Do not let it sit longer than this because you want the water to have air in it or the process will go anaerobic and kill all the microorganisms. Or you could bubble air through it to keep the microorganisms alive.

The soaking will leach out a lot of the nutrients and microorganisms (goodies). Happy Frog still has a lot of microorganisms in it. Many do not. Use this gallon of water to water your flowering cactuses.

If you want a mineral fertilizer, then any fertilizer made for tomatoes or roses will do well. Just use very small quantities. Products to look at include Peters, Miracid, Miracle-Gro and Jobes.

Most important for cactuses, make sure you amend the soil with organic material such as compost or some manure-based amendment when you plant them. Cactuses do much better in an amended soil than pure sand or our unamended native soils. If the soil was not amended, lift them during the warm months and replant them using soil that drains freely and has compost incorporated into it.

Bob Morris is a horticulture expert living in Las Vegas and professor emeritus for the University of Nevada. Visit his blog at