Thursday, January 8, 2009

Pyracantha


Question: Can you suggest a good screen plant that will deter people from easily accessing my back yard? I do not want a fence but would like a little added security.


Answer: The plant that pops up in my mind is a pyracantha. Winter is often when I think of this plant because it has showy fruit until the cedar wax wings and other birds clean them off. Pyracantha is a member of the rose family and, like its cousin, has an abundance of thorns. The thorns are much larger and more painful to encounter than roses. My dad always said nothing will keep determined intruders out, but pain will do a good job deterring ‘honest’ folks.
Although pyracantha can be maintained as a four or five foot shrub, it would be better if you did not have to prune it very often due to the aforementioned pain. The ultimate size of most varieties will be about 10’ by 10’, so it does not take many plants to make a living fence. The plants can be planted somewhat closer for quicker fill but remember to allow plenty of depth for them to spread. They are fast growers that are adapted to many soil types, except poorly drained soil.


Winter is a great time to plant them. Dig the plant hole as wide as practical but at least twice as wide as the root ball. To avoid plant settling to a position deeper than desired, do not dig any deeper than the root ball. I always like to pull the plant from the container and wash off most of the bark from around the roots. This will allow you to spread the roots out laterally in the wide planting hole and will prevent air pockets which would develop when the bark slowly decays after planting.


The first year after planting pyracantha will need supplemental watering to get them well established, but once established they are pretty tough plants. Keep the area around the plants weed free and do not use weed eaters around the base. Three inches of mulch over the root system can go a long way in helping control weeds and retain moisture. Do not pile mulch thickly around the base of the plants.


Although pyracantha is not a native plant it is widely adapted and the native birds and wildlife do love the fruit they produce. Pyracantha can also be used in floral arrangements to add a splash of color and a distinct texture. Most varieties have bright red berries but there are some yellow and orange fruited varieties available. If the standard sized plant is too big for the area you have in mind there is a compact selection called Red Elf. This might be a good choice for underneath a window to deter an intruder or peeping Tom.Two serious problems on pyracantha are fire blight, a bacterial disease that can kill the plant, and scab, a fungal disease which causes defoliation and turns fruit a dark, sooty color. To minimize problems, choose disease-resistant selections such as ‘Apache,’ ‘Fiery Cascade,’ ‘ Mohave,’ ‘Navaho,’ ‘Pueblo,’ ‘Rutgers,’ ‘Shawnee’ and ‘Teton.’ For further information on growing this useful and beautiful plant visit here.

Friday, December 12, 2008

Mistletoe



Question: Can you tell me about the harmful properties of mistletoe and whether or not it is poisonous to people?

Answer: Mistletoe is an interesting group of plants with an interesting history. On a worldwide basis mistletoe may generically refer to any of more than 200 species of semi-parasitic shrubs found worldwide. However, according to Curtis J. Hansen, Curator Freeman Herbarium, Auburn University there is primarily only one species of mistletoe that dominates the eastern United States and that is the “Oak Mistletoe”, or scientifically speaking, Phoradendron leucarpum. It sounds very romantic in Greek but literally means "tree thief". Maybe that’s where the idea of “stealing” a kiss under the mistletoe originated.

All mistletoes are parasitic, meaning they grow into a host tree and "steal" nutrients for growth. However, they are also green, so they can produce some of their own nutrients through photosynthesis. While most mistletoes don't outright kill their tree-host, they can weaken them over time and ultimately be the cause of tree death. As the name indicates, Oak Mistletoe is found mostly in oak trees, but may also be found in other hardwoods. This particular species isn't known to grow in pines or conifers in our area. Mistletoes are particularly easy to spot at this time of year when the leaves of the hardwood trees have fallen. In fact, you may find many plants in full fruit with little white berries, for female plants and male plants that are in full flower. There are separate female and male plants within this species.

The parasitic properties of mistletoe are often duplicated by the men I see hovering around the sprigs at Christmas parties. Rather than true roots, the plant has extensions called holdfasts that grip the host plant. With the holdfast the plants take what they want from the host plant (again not unlike the aforementioned men).

In the South, tiny yellow flowers bloom on the evergreen mistletoe from fall into winter. The familiar white berries begin to form soon after pollination and resemble little packets of glue around tiny indigestible seeds. Although eating mistletoe berries may potentially be lethal for humans, birds seem to be immune to any toxicity.

The immunity of birds to mistletoe's poisonous qualities is essential to the welfare of the plant. The dispersal and propagation of mistletoe is largely dependent on birds that eat berries but do not digest the seeds. Studies suggest that seeds are most likely to survive and grow if a bird deposits them on the same species of tree on which the parent plant lived.
The use of mistletoe as a romantic lure stems from England at least as early as the 1500s. A version of the tradition persists today in secular Christmas decorations. Mistletoe has an interesting story behind its name. Several hundred years ago, it was thought that the mistletoe plant was formed spontaneously from bird droppings. Of course no one thought to look inside the bird droppings for a concealed seed. However, due to this error, the plant was given the name mistletoe which translates literally in English to “dung-on-a-twig.” I think we should stick with the name mistletoe because “meet me under the dung-on-a-twig” just doesn’t set the right festive mood.

Monday, November 24, 2008

Choose a Christmas Tree

Question: I love to use a real Christmas tree but the needles are always a mess. What type tree has the least problem with needle shedding?

Answer: The quick answer is "the fresher the tree, the better it will hold its needles." The only way to know you have a freshly cut tree is to cut it yourself, or in my case, I just point to the tree and tell one of my sons to cut it for me. If you buy a tree from a local "choose and cut farm," it probably doesn’t matter what species you purchase. The key to keeping the needles attached is to get the fresh cut tree stump into water as quickly as possible.

Choosing a pre-cut tree from a sales lot can be a little riskier than cutting the tree yourself, but if you follow these tips your chance of getting a good tree will improve greatly. Purchase a tree as soon as trees are available even if you don’t plan to decorate it for several days. The sooner you can get the tree in water the longer it will last. Most of the trees on sales lots were cut at the same time, so the longer they stay on the lot without water, the less likely the y will even take water up when they are placed in home tree stands with water reservoirs. Look at the tree trunk near the base and if you see splitting, the tree most likely has dried so severely it will not absorb water.

Look for a tree with a healthy, green appearance and few dead or browning needles. Run your hand along a branch to see if needles seem fresh and flexible. Needles should definitely not pull free easily. If possible, bump the base of the tree on the ground. You should expect some of the old dead needles to fall off, but if green needles also fall off, the tree is not very fresh.

Once you have chosen that perfect tree and have arrived back home safely, you should make a fresh cut a couple inches above the original cut. This removes any clogged wood that would prevent water uptake. If you are not ready to place the tree indoors you may store in a shady area outdoors or in an unheated room or basement. Regardless of where you locate the tree, make sure to check the water reservoir frequently and keep it filled a couple inches or more above the tree’s base. I have not seen any research that proves any concoction added to the water works significantly better than plain tap water.

Another tip to consider involves tree location in the home. Keeping the tree away from heat sources such as air ducts, wood stoves, and fireplaces will prolong the freshness and reduce the risk of fire. Make certain all lights and extension cords are in good working order and turn lights off when the tree is not attended. Because our homes are much drier in the winter when the heating system is operating, a small room humidifier can be good for you, your house plants and Christmas tree.

Some trees are just naturally better at retaining their needles. Douglas fir, Eastern White Pine, Fraser fir, Leyland Cypress, Scotch pine and Virginia pine are considered to have excellent needle retention. Freshness, however, is the key to needle retention.
If you would like some additional tips and a list of the pros and cons of the most popular species, click here.

Friday, October 31, 2008

Winterizing Warm Season Grasses is a No No


Question: The lawn care company recently applied an application of “winterizer” fertilizer to my Bermuda grass. Do you recommend winterizer fertilizer on warm season grasses?

Answer: If this is a well established lawn it is doubtful you need a fall application of fertilizer unless a soil test indicated a low level of potassium. Unfortunately, there are many products on the market sold as winterizer fertilizer. Cool season grasses such as fescue do most of their growing in the fall and spring and they need nitrogen to grow. However, many of these products are also used on warm season grass. Fall nitrogen application can be damaging to warm season grasses. Instead of increasing the cold hardiness, the opposite effect results. A warm fall will lead to continued vegetative growth which sets the plants up for cold damage. Check with your lawn care company and ask for the analysis of the fertilizer used. If the first number is 5% or below, it probably won’t hurt but it would be better if no nitrogen is applied to Bermuda and other warm season grasses after August.


I would suggest you have your soil tested to see if you need potassium or not. If you fertilize during the summer months it is very doubtful extra potassium in the fall will provide any benefit. However, if you do apply fall fertilizer, always apply it onto dry foliage to reduce the likelihood of salt burn.


A soil test provides a wealth of information and can be done for only $7 in Alabama and many state Extension offices offer similar services. Fall is a great time to test the soil because the lab is not as busy and if you need lime you have time to get it out on the lawn before spring growth starts. The lime will slowly move into the soil with winter rains and the pH will gradually rise in time for the first spring growth spurt. Once you receive your test results you may want to contact your local Extension office to talk with a horticulturist about your test results.
I have seen many test results that indicated an excessively high level of phosphorus and potassium. Phosphorus does not leach from the soil very quickly and it can build up to the point that no phosphorus will be needed for many years. Potassium can become so high that it interferes with the uptake of other elements such as magnesium and can result in a lighter green turf color. Also, be aware that an excessively high rate of potassium fertilizer can cause foliar burn.

Monday, October 13, 2008

Fall Is For Planting


Question: I am planning on planting some trees and shrubs this fall and would appreciate some planting tips to insure success.

Answer: Most of the time I get questions after newly planted trees and shrubs start to die, but I much prefer offering pre-planting advice to avoid problems.

Fall is the best time to plant most perennial plants including trees and shrubs and even most herbaceous perennials. The keys to success start even before planting perennials in the ground. It is always advisable to do a little research on the front end. There are some important questions you should answer before planting anything. One, are the plants I have in mind adapted to our climate? And I don’t mean adapted just to cold, but also to heat which is often as important as cold in our area. Two, will the plants tolerate the drainage within my soil? Poor drainage causes more plant death in heavy clay soils than drought does. Third, is the site chosen adequate for continued growth of the chosen plants? You should always think about the mature size when choosing the planting location and plant material.

The actual planting process will determine in large part the future growth and possibly whether or not a plant survives at all. There are at least two myths about planting woody plants that reduce your chance of success.

The first myth is that you should amend the planting hole with loose organic matter. If you have a lot of clay in your soil you should not use any organic soil amendments. There are several potential problems with adding organic matter and they all revolve around water. If organic matter is added to a hole surrounded by heavy clay soil, the water movement is drastically altered. You will have one of two problems. Either the water will not move out of the hole after rainfall, causing a bathtub effect, or the organic matter will dry and not re-wet well. Both of these scenarios will lead to root death. Plant wilting is not a good indicator of whether the soil is too wet or too dry because drought and excessive water both cause wilt.

The second myth is that you should not disturb the root ball coming out of the container. This myth relates to the previous myth, but needs some further explanation. Most plants are grown in containers at the nursery in a very light ground pine bark mix. This mix is great for growing shrubs and trees in the nursery but can present terrible problems in the landscape. If this loose bark is allowed to remain intact, the water movement issues described above still apply, with the added problem of air pocket development around the roots as the bark decomposes. Therefore, it is best to gently wash most of the loose bark material off the plant until it is, for all practical purposes, a bare root plant. This may involve pulling the roots out if they have started winding around the root ball. If necessary you can prune or slice these roots to help make this job easier, but try to leave as many roots intact as possible.

The planting hole should be shallow and wide. The depth only needs to be as deep as the root ball, but the hole should be two to three times the width of the longest lateral roots. Look for the uppermost lateral root to determine the planting depth. This lateral root should be at grade or slightly above the surrounding soil grade. Make a small ring of raised soil to hold water near where the outermost roots extend. Keep this area moist at all times for the first several weeks and then gradually decrease watering frequency and increase watering depth to encourage deeper rooting. Mulching the root area can give you a false sense of security about whether the plant has adequate water. It is very important to check the root area frequently to avoid drying. Do not apply mulch more than a couple inches thick.

A couple other post plant care tips are to keep the area around trees and shrubs weed and grass free, widening the weed free area as the plant grows. Also, avoid using weed whackers or mowers near the plant base.

Monday, September 29, 2008

Sweet Tea Olive


Fall is a great time to visit the Birmingham Botanical Gardens for many reasons but the fragrance coming from sweet tea olives is highest on my list. Tea olives are in the plant Genus Osmanthus which comes from the Greek and means “fragrant (osma) flower (anthus)” and it certainly lives up to the name. Tea olive, as the name indicates, belongs to the Olive Family (Oleaceae) along with numerous jasmines which are also very fragrant. The usually white blooms are small and not extremely showy and I am not surprised you could not tell where the fragrance originated. Even though individual blooms are small some cultivars have clusters large enough to add some floral interest. Tea olives are very nice evergreen shrubs with holly like foliage. You can easily tell the two apart even when not in bloom by looking at the leaf arrangement. Hollies have leaves arranged alternately down the stem and tea olives have an opposite arrangement.

There is a large planting of Osmanthus x fortunei 'Fruitlandii' at the BBG that makes a wonderful screen planting that is a pleasure to walk near. The mature height of tea olives may vary from six to thirty feet depending on the species and cultivar. I lived in Mobile in the past where the “fragrant tea olive” Osmanthus fragrans was the most commonly planted species. It is less cold tolerant but will survive in central (possibly north) Alabama in a protected micro-climate. It would be best to locate this plant on the south or southwest side of a structure. Much like camellias the main risk from cold is the rapid freezing and thawing action that is worse with a morning sun exposure. As the name seems to indicate it is the most fragrant of all the tea olives and therefore may be worth the risk of occasional cold damage. It also has the longest bloom period with blooms possible in every month with the letter “R” included.

In general all the tea olives will grow in full sun to part shade but in the central southeastern United States I would suggest a site with a break from the afternoon sun. Once established they are fairly drought tolerant but it may take a couple years to become established. Fall is a great time to plant and will require less care than spring or summer plantings. Choose a well drained area with slightly acidic soil for best results.

Tea olives are really quite easy to care for once established and have very few pest problems. If pest problems do occur it is probably due to stress from poor soil conditions or drought. Scale insects may flare up from time to time but can be controlled with horticultural oil sprays. Minimal pruning is needed unless they get too large. If you do prune them do so in the late winter to avoid removing the flower buds which form on the new growth each spring and summer. The exception to this rule would be the Delavay tea olive (Osmanthus delavayi) and our native Devilwood (Osmanthus americanus) which bloom in the spring and should be pruned just after blooming like other spring blooming plants.

Devilwood is the only native tea olive and is native to swamps and stream banks in the southern US including south Alabama. The name comes from the extremely hard wood which is a “devil” to split and work. The leaves are larger and less holly like than other tea olives. Like other tea olives the flowers are quite fragrant but they occur in early spring on last year’s growth. This native plant is more tolerant of wet soil conditions but is adaptable to most Alabama soils. It would be a great choice for a rain garden because it tolerates frequent flooding and can take the drier times between rain events.

Regardless of which tea olive you plant you are sure to be enchanted by the sweet aroma they produce and yes they can be used in tea.

Wednesday, September 3, 2008

Pruning Encore Azaleas

Many people ask how to prune Encore Azaleas and a picture is worth a 1000 words - so take a look.