What Vegetables Can I Plant in March?

Here is a list of vegetables you can plant in March in the Las Vegas Valley. The Las Vegas Valley is around 2000 foot elevation (650 meters). Lower elevations can start earlier than this. Higher elevations can delay planting a bit.

March

Bush beans (s), broccoli (s,T), brussels sprouts (T), cabbage (T), carrots (s), sweet corn (s), eggplant late in the month (T), green beans (s), pole beans (s), kale (s), kohlrabi (s), lettuce (s), onion sets, onions (T), peppers late in the month (T), potatoes, radishes (s), spinach (s), Swiss chard (s), tomato late in the month (T), turnip (s)

T= tramsplants are best

s= cam be started by seed

You Can Still Prune after New Growth Starts

Q. Took your recommendation and planted a Dapple Dandy pluot and Santa Rosa plum in the same hole about 18 inches apart. New growth has already started to appear. What I’d like to do now is cut and lower the height of the Santa Rosa plum to the same height as the pluot. Is it too late to do that?

Pluot and plum planted in the same hole. Santa Rosa plum is one of the best pollinators for Pluots. The fruit trees are whitewashed to help prevent sunburn.

A. No, it is not too late to prune. People are mistaken when they think the only time to prune is during the winter months and when new growth appears, it is no longer permitted. This is a not correct.

            One of my professors used to say, “The best time to prune is when the pruners are sharp.” I still agree with him. However I would alter that by adding, “as long as it is a hand pruners.” If you are removing large diameter wood using a saw or loppers timing is more critical.

            In short, go ahead and lower the height of that pluot. Make sure you whitewash the upper surfaces of any exposed limbs to reduce sunburn unexposed branches. I will talk about summer pruning next month. I will post more about this topic on my blog.

Be Careful with Fertilizers for Tomatoes

Q. I was reading an older article from Linn Mills about foliar fertilizing tomatoes. Linn was saying to spray tomato plants with phosphorous. I read an organic article in which they use fish-seaweed extract in your opinion which is better to use?

High phosphorus fertilizers do not cause all vine and no fruit

A. Great advice from Linn! You want to give tomatoes a complete fertilizer at the time of planting. You can use organic sources or conventional fertilizers. It will not make much difference to the plant.

These can be applied to the soil or to the plant leaves if they are a liquid. After an initial

application of a fertilizer, phosphorus should be in abundance, not nitrogen, with further applications.

The problem with organic sources like compost added to the soil at the time of planting is that the fertilizers or nutrients they contain last so long. This is because the nitrogen in the compost is released slowly over a period of several months. This is not true of organic foliar sprays like seaweed extracts.

An overabundance of compost added to the soil will cause tomatoes to produce a lot of vine and delay flowering. This is not necessarily true of their close cousins, peppers and eggplant. If flowering is delayed in tomato and begins during the heat of the summer, it can result in little to no fruit production.

Example of a high phosphorus foliar fertilizer
to stimulate flowers and fruit

Inexpensive conventional fertilizers (farm fertilizers) release its nutrients quickly. One big shot is released during the first few irrigations and the amount of fertilizer available to the plant diminishes quickly after that.

These quick release or conventional fertilizers, at least the nitrogen component, lasts four to six weeks and 80% of it is gone. Quick release fertilizers, applied at planting time, are perfect for tomato growth and fruit production.

Foliar fertilizers, fertilizers applied as a liquid to the leaves and stems, act very similarly to quick release fertilizers applied to the soil. Liquid fertilizers applied to leaves last a very short time; 2 to 3 weeks.

Foliar fertilizers need to be applied more often than fertilizers applied to the soils. Foliar fertilizers should always contain a wetting agent to help that fertilizer gain entry inside the plant.

We want tomato plants to gain size quickly for about four weeks before they set fruit. If nitrogen is released in large amounts after that time, it will likely cause a delay in flowering and put on leaf and stem growth instead.

Example of a 1:1:1 fertilizer

If you are foliar feeding, you should have at least two different types of foliar fertilizers, maybe even three. The two which are most important are a high nitrogen content (highest first number) fertilizer and the second is a foliar fertilizer with high phosphorus content (highest second number).

If you get a third one then make it a fertilizer in a 1:1:1 ratio of nitrogen, phosphorus and potassium. Whenever possible make sure the third number, potassium, is also high in all three

fertilizers or make sure it is applied to the soil and available to plants.

Help Save My Photinia from Dying

Q. Our red tip photinia appears to be dying. It is 8 years old and receives full sun. The leaves are turning brown and dry.  Is there a disease causing this or is it the very hot weather we have experienced this summer?  We fertilize and  apply iron regularly.

Photinia with iron problems and soils with lack of organic matter

A. The usual problem with Photinia occurs when their planted in desert landscaping with rock mulch covering the surface of the soil. They are planted with some soil amendment in the planting hole which disappears in two or three years. Sometime during the fourth and fifth year Photinia begins to develop yellow leaves.

Photinia with the beginning of the decline

These yellow leaves become a brighter yellow and begin to scorch around the edges. If this problem is not fixed, Photinia gets worse and we see die back of the stems and the canopy of the plant opens up and looks very sparse. The problem is the rock mulch for this plant. They do not like it. They like organic soils, not soils covered in rock.

You have two options. Pull the rock mulch back and add compost to the soil around each of the Photinia about an inch deep and scratch it into the surface. Next cover the area with wood mulch, not rock mulch.

Add iron fertilizer and a regular fertilizer to the plants. Water them in thoroughly with a hose. Cut the Photinia back close to the ground and let it regrow. Hopefully this will get them off to a good start this spring. Continual additions of compost every two years will help this plant stay healthy.

The second option is to dig and remove these plants and start all over. Make sure the soil they are planted in as 50% compost mixed with it. Cover the soil with wood mulch and grow them out. Fertilize once a year in January with the commercial fertilizer for trees and shrubs and make sure you add an iron fertilizer at the same time.

Starting Texas Mountain Laurel from Seed

Q. I harvested some Texas Mountain Laura. Can I expect them to grow if I plant them in garden soil? Should I remove the outer shell first?

Texas mountain Laurel dried seed pods

A. Texas mountain Laurel can be started or propagated from seed but there is at least one major hurdle you must overcome. This hurdle is the very hard coat around the seed, not the pod.

The seed is best harvested from pods that have not fully matured. If possible harvest the seed from pods that have not yet turned brown but give you a clear indication that there is a seed which has fully formed.

Texas mountain Laurel

For seeds to germinate they must absorb water, be at the right stage of development, have warm temperatures and air. This very hard seed coat does not permit water to enter the seed and begin the germination process.

 To my knowledge, this seed does not have to be stored in cold temperatures prior to starting them from seed. Some seeds from temperate climates have to go through a simulated winter in the refrigerator before you plant them or they will not germinate. 

This seed does not seem to need this. However, to be on the safe side take half of your seed and give them an 8 week cold treatment in the fridge and take the other half with no cold treatment and see what happens. Give them a cold treatment before you damage the seed coat.

Damaging the seed coat without damaging the seed permits water to enter and start the germination process. If the damage to the seed coat is too deep, the seed may die.

           The easiest way to damage the seed coat safely is to use a file or sandpaper and scratch or nick the seed coat deep enough so this barrier is breached but not deep enough to damage the seed itself.
           There will be some variation in these plants because they are propagated sexually, that is by seed. When these seedlings first come out and reach about 1 foot in height you can begin to discard plants that don't have the size or shape that you desire. This is called "roguing" out the seedlings.

Here is a good website to look at.

http://uts.cc.utexas.edu/~harms/MtL-seed.html

This website seems to say it needs a cold treatment

http://homeguides.sfgate.com/grow-mountain-laurels-seed-25353.html