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Wednesday, January 20, 2016

Do You Love Magnolias?

2016 Magnolia “Seedling” Program

The Magnolia Society International is excited to announce a new scholarship program, the Magnolia “Seedling” Program. This seedling program is a new endeavor targeted to support a young magnoliaphile to attend an annual meeting by paying their expenses (travel, lodging, meals and registration). MSI wants to encourage someone who is just starting out in horticulture or research and has a specific interest (breeding, conservation, production, etc.) in magnolias. 

The 2016 annual meeting is April 8-11, 2016 in Philadelphia, Pennsylvania. More information about the meetings can be found at www.magnoliasociety.org. If you have a student that you feel qualifies for this travel scholarship please send a nomination including name of individual, statement on why you feel they deserve the travel scholarship and their specific interest with magnolias. There is a short deadline of January 30th, 2016. Please email nomination to:

Dr. Todd West

266E Loftsgard Hall
Dept 7670, PO Box 6050
Fargo, ND 58108-6050

Fax: 701.231.8474

Monday, January 18, 2016

All Rosemarys are Not Created Equal

Q. I use rosemary which I purchase from the store for cooking.  It is expensive and does stay fragrant very long if I don't use it all. I would like to plant rosemary in our yard so that I can use it in my cooking.  Is there a difference between rosemary used for "cooking" and rosemary used in landscaping?

A. There are several varieties of rosemary but most are selected for landscaping rather than cooking. Many of the landscape varieties have horizontal or prostrate growth. However, these landscape varieties can be used for cooking as well. But varieties selected for cooking are usually upright and often have a higher oil content. Upright growth is easier to harvest.

Rosemary comes in both upright forms and prostrate. Upright forms are easier to harvest.
Growing rosemary as an herb is different from growing rosemary as a landscape plant. Two traits are considered desirable in rosemary as an herb; upright succulent leaf and stem growth and a high oil content.

To grow rosemary for cooking, push new growth with nitrogen fertilizers and harvest before flowers are produced. Seldom is rosemary left to flower when used as an herb but the new growth is dried or used fresh. Flowers may be attached when sold at Farmers Markets.
Rosemary flowers contain the most and better oil. Commercial producers focus on leaf and stems for oil production because it is easier to produce even though the oil is not high quality.

The best oil comes from rosemary flowers. However, most commercial oil production is from leaves and stems which produces more abundant oil but it is inferior to the oil produced in the flowers. The same technique is used except high phosphorus fertilizer is applied to improve oil production and harvesting is done when flowers are present for higher-quality oil.

Some of the better varieties for cooking include Benenden Blue, Flora Rosa, Tuscan Blue, Majorca Pink, Arp, Albiflorus, Huntington Carpet, McConnell's Blue, Irene, Holly Hyde and Hill Hardy to name a few. 

Spittle on Rosemary a Common Problem

Q. My rosemary plant has white foamy droplets on the stems. I can spray them away when I water with a hose but they return. They do not seem to be harming the plant but what is it?

Spittlebugs are common on rosemary and live within the spittle for protection

A. The white foamy droplets are called spittlebugs and common on rosemary. They suck plant juices and are buried inside the spittle for protection. They can be knocked off the plant with a strong stream of water from a hose but they return quickly.
They are usually more of a nuisance than a problem unless you are growing rosemary as an herb. They can multiply and become a problem in the future so keep an eye on them.
Neem oil and horticultural oils will give some control of spittlebugs when sprayed directly on the plants. Spray a small section of the plant first to make sure the oils do not damage the rosemary.

Soap and water sprays wash the spittle off and leave these bugs unprotected. Follow this with an insecticide spray such as pyrethrum which protects the plant from becoming reinfected. This might need to be done several times, a few weeks apart, to get them back under control.

More Rosemary Dying

Q. My Tuscan rosemary is in trouble. It appears to be dying.

A. Tuscan is a nice upright rosemary variety with good color and density that is grown for cooking and its oil content. It has very few insect and disease problems. We will occasionally see aphids and spittle bugs but nothing to get overly excited about.
Tuscan is an upright rosemary variety good for herb production
            Rosemary prefers soils that have been improved with compost and organic surface mulches such as wood chips. The soils must drain well. They do not like rock mulch at all and frequently die a few years after being planted.
When these plants die it is usually due to soil problems. Roots have a tough time "breathing" because of poor drainage. Most of the time these soil problems cause the roots and stem of the plant to die. The plant collapses during the heat of summer because roots are dead.
Avoid planting rosemary in low spots or where water accumulates. These conditions suffocate roots. It is possible to replant in this spot but remove as much of the soil as possible and replace it with the soil that drains easily.

This particular root disease may linger in this infected soil and cause future problems. 

Rosemary Dying Usually Soil Problem

Q. Can you tell me what is killing our rosemary hedge, by inches?  The plant is 15 years old.  Other rosemarys of the same age on the property are still thriving.  Any help would be appreciated.  Picture attached. Thank you

A. There are a few insects such as spittle bugs that get on rosemary but there are not that many diseases that affected except some of the soil borne fungal diseases. In other words, these are disease organisms that are already present in the soil but they need opportunity in order to take advantage of rosemary. When soils remain wet, this stresses rosemary and makes it susceptible to these types of diseases. The usual advantage these diseases get is because soils are from plant stress because soils are kept too wet from frequent irrigations or the soils do not drain water fast enough before the next irrigation.
Rosemary dying is usually a soil or irrigation and drainage problem.

These diseases attack the roots of the plant and cause dieback of the top similar to what appears to be drought. It appears to be drought because the roots are dying and they can no longer take up water to the tops so, in fact, it is drought but drought caused by too much water present around the roots.

Like many Mediterranean plants, rosemary does not like wet soils in the summertime. They can tolerate wet soils as long as there is drainage and the soil has enough time to dry out between irrigations. These types of diseases frequently start at low spots in the irrigated area where water collects or puddles. Usually plants growing where the water has drained to low spots remain healthy.

Plants that have extensive root rot from soil disease organisms frequently will pull from the soil fairly easily or are loose in the soil when they are pulled from side to side.

The solution? The usual solutions are to water less often or improve the drainage in the soils or both. Rock mulches around rosemary will cause the soil to become more compacted and not drain water well. Organic wood chip mulches help to keep the soil "fluffy" and improve drainage. Organic wood chip mulches help to keep soils more moist so the frequency of irrigation typically has to be less. 

If this problem was caused from soil disease organisms it will be difficult to reap plant rosemary in that soil again. You might have to remove the soil from that spot and replace it with an amended soil before you replant another rosemary in that same location.

Rosemary Not Flowering

Q. I have an upright rosemary about four feet tall. It was sheared once on the top and the sides. It has never bloomed. Is there such a variety that never blooms or am I doing something wrong with this plant?

A. I have never heard of one not blooming. Most reasons plants do not bloom are planting them into low light levels (shade) or shearing them just prior to bloom. Normal bloom periods are spring and fall but in warm areas they might bloom all season long.
Rosemary is a prolific bloomer in the spring and fall if it receives enough light

Pruned during the summer months if you want the blooms. Pruning in the spring or fall cuts off the flowers. Make sure it receives plenty of sun and do not plant in the shade. Avoid high nitrogen fertilizers but use fertilizers recommended for other flowering plants such as roses.

Sunday, January 17, 2016

Prune Rosemary Now If It's a Bush

Q.  When is the best time to prune a rosemary bush? Our rosemary bush has grown too large.  I would like to reduce it to about one-half of its current size. Also any suggestions about how I should prune it would be greatly appreciated.

A. If you are pruning it once a year, now is a good time. If you are pruning it as a hedge or you have to keep it under some sort of size control, then prune it once a month. If you are pruning it to use it for herbs, cut it back now, let it regrow and harvest the new, succulent growth before it flowers.

You have a few alternatives. One method cut it to the ground and let it regrow from one or 2 inch long stems. Prune it now or just before new growth begins.

Another method requires more care.Trace the longest branch of the shrub inside the plant and remove it where it joins a main branch. Leave no stub. Select two or three other long ones to the inside and make the same kind of cuts. Do this every couple of years when it starts to get too large.

Your third alternative is to replace the plant with something that doesn't get so large. 

After pruning, fertilize it as you would normally to encourage new growth. One fertilizer application a year is all that is needed unless you are growing it as an herb that requires frequent harvesting. If you are harvesting frequently, fertilize lightly every 6 to 8 weeks with a balanced fertilizer containing nitrogen and phosphorus. Or apply your favorite compost to the base of the plant and you'll get more spectacular results.

Overgrown Privet Is a Goner

Q. I have a neglected privet that has overgrown its space. When and how far back should I prune it and keep its shape? My neighbor cut one back several years ago and it never came back at all.  Thanks.

A. I may have some bad news for you. I looked at the picture and I am guessing most of the leafy growth is out towards the edges of the plant and on the inside will be bare branches. 

If your pruning cuts are made back to the inside of this plant where there is no leafy growth, re-growth from these cuts will be either slow or they won't regrow. Regardless, this plant is going to look bad for a long time after these pruning cuts are made. 

This is really a case where you have a plant that was just too largeat maturity placed in a spot that was just too small. 

Really your best alternative will be to replace it if you want to look nice. It is possible to make some deep cuts and it may regrow but these cuts will have to be done just to the outside of some buds and done very carefully

Dog Urine and Lawn Problem? Follow me and find out.

I had a question submitted to me regarding dog urine on a lawn and how to stop the damage. It can be found here.... (mouse right click on the link below to read it)


I recommended following the dog with a bucket of water.

I received an email about a product called Dog Rocks.... You can follow the emails in the comments at the bottom of this post.

http://dogrocks.org/ (mouse right click on this link to learn about it)

I was contacted by the CEO Dog Rocks USA LLC & Dog Rocks UK Distribution Ltd and she agree to supply it if we would try it. I contacted the person with the question to me and he agreed to try it provided it was supplied by the manufacturer. I agreed to post the results...positive or negative...after trying it. The CEO is following up on this trial and I will be in the loop.

Follow me and find out the results later in the summer of 2016.