Lawns, Gardens & Trees
It is often confused with clover and black medic in leaf form. Oxalis has distinctly heart-shaped leaflets that are always lighter or yellowish green. This is a unique weed in that it has both an annual and perennial forms; the flower and capsule are what warrant special comment. The flower is yellow and tubular with 5 petals, and when the capsule matures, it expels seed, doing so with great momentum, scattering the seed like birdshot in multiple directions several feet away. The seed pod is erect, hairy, cylindrical, 1/3 to 1 inch long, and pointed at the tip. This weed is a curse to have in greenhouse environments and can go from being insignificant to a real headache is not controlled early in detection. Control this weed with Weedone DPC amine or Trimec.
Harvesting and Curing Gourds
Gourds are ready for harvest when the stems dry and turn brown. It is best to harvest gourds before frost. Mature gourds that have a hardened shell will survive a light frost, but less developed gourds will be damaged. The lagenaria will tolerate a light frost; but gourd color may be slightly affected. Gourds should be cut from the vine with a few inches of the stem attached. Take care not to bruise the gourds during harvest, as this increases the likelihood of decay during the curing process. Discard any fruit that is rotten, bruised or immature. After harvesting, gourds should be cleaned with soap and water, dried, and rubbing alcohol applied to the surface.
Curing cucurbita gourds is a two-step process which may take 1 to 6 months depending on the type and size of the gourd. Surface drying is the first step in the curing process, and takes approximately one week. During this time, the skin hardens and the exterior color of the gourd is set. Place clean, dry fruit in a dark, well-ventilated area. Arrange gourds in a single layer and make certain that the fruits do not touch each other. A slatted tray will allow air circulation around the gourds. Check gourds daily and discard fruit that show signs of decay or mold and any that develop soft spots.
Internal drying is the second step in curing and takes a minimum of four weeks. Keep the gourds in shallow containers in a dark, warm, well-ventilated area. If any mold appears on the outside skin, gourds can be wiped clean and allowed to continue drying. However, any gourds that become decayed, shriveled or misshapen should be discarded. Periodically turn the fruit to discourage shriveling and promote even curing. Providing warmth during the internal curing process will accelerate drying and discourage decay. Adequate curing is achieved when the gourd becomes light in weight and the seeds can be heard rattling inside. Cured gourds can be painted, waxed, or decorated.
Lagenaria gourds can be surface cured in the same manner as cucurbita gourds. However, the internal drying process takes much longer for the gourds to fully harden. After curing, the surface can be smoothed and polished with very fine steel wool or sandpaper. The hardened shell should be treated with rubbing alcohol, allowed to dry, and then waxed or shellacked for the final finish.
Luffa gourds have specific harvesting and processing techniques to produce high quality sponges. Harvest when the outer shell is dry, the gourd is light in weight and the seeds rattle inside. Remove the stem end of the gourd and shake out the seeds from the center cavity. Soak the luffa gourds in warm water until the outer skin softens to the point where it can be easily removed. Then soak the fibrous sponge in a solution of 1 part bleach to 9 parts water to obtain the desirable creamy-white appearance. Rinse in clear water and allow to dry before using.
Darkened areas and pitting occur in the outer skin of the apple. Corky, brown tissue forms inside toward the blossom portion of the fruit. Bitter pit is a disorder that is caused by a deficiency in calcium.
It is a beneficial insect that eats aphids and other insects. The larvae appearance has caused many homeowners unnecessary concerns.
Asparagus can be damaged by the beetle in different ways. Larvae and adult will give the spears/tips scarring. Droppings or frass can stain the spear and be unsightly.
Handpicking or brushing them to the ground with a towel or small broom is what is done in small garden situations for control.
Leaves normally change color in the fall – we all know this. If leaves begin to change color in the summer, that’s usually not a good sign. Insects, diseases, nutrient deficiencies, environmental stresses – or some combination of these – can all cause leaves to turn yellow, brown or other colors during the growing season.
However, some trees and shrubs are supposed to have two-toned leaves during the growing season. On other trees, you may see individual leaves of one color, and other (individual) leaves of a different color. In some cases, that’s okay! See the pics below.
‘Schubert’ chokecherry – ‘Schubert’ chokecherry (a.k.a. ‘Canada Red’ chokecherry) is valued for its purple foliage during the growing season and bright red fall color. The bright green leaves at the tip of this branch are a new flush of growth appearing in mid-season, and they will turn purple in one to two weeks. This variety of chokecherry is native to North Dakota and is extremely hardy. Suckering from the roots may cause problems.
Poplars –This hybrid poplar produces leaves that start off with a purple hue which then change to green – just the opposite of the Schubert chokecherry. There are many poplar trees that are either native to North Dakota or adapted to the environment here. Most poplars grow quickly but die young – especially the hybrids. This can be handy when establishing a windbreak, as the poplars can provide immediate protection while the more-permanent trees establish slowly.
Ivory Halo dogwood – This species has variegated leaves. That is, the leaves are naturally two-toned. There are many other trees and shrubs that are variegated, but finding ones that are tough enough to handle the North Dakota environment can be difficult. Ivory Halo is hardy to Zone 3, and it does best in protected areas with good soil moisture.
Is Master Gardener training on your bucket list? Do all your friends and neighbors come to you for gardening advice? Would you like to learn even more about horticultural topics from NDSU professionals? Registration is now open for the 2013 North Dakota Master Gardener Program! We are delighted to offer both classroom and online training. The classes will run from September 27 through November 15th. If you have questions, contact Esther McGinnis, Master Gardener Coordinator (701-231-7406) or your local Extension agent. See the following website for more details: http://www.ag.ndsu.edu/mastergardener/
NDSU-Department of Plant Sciences will host an open house to celebrate its historic daylily collection on July 29, 2013 from 9:00 a.m. to noon. The NDSU Daylily Garden is an official display garden of the American Hemerocallis Society and features over 1200 pre-1980 cultivars. This is the largest daylily planting at any land-grant university in the nation. The garden is located at the corner of 12th Avenue North and 18th Street. A brief presentation will take place at 10:00 a.m. to honor Mary Baker, former regional vice president of the American Hemerocallis Society. Ms. Baker was instrumental in saving the garden from being destroyed by construction and mounted a national letter-writing campaign that ultimately convinced former NDSU President Joseph Chapman to preserve this unique garden. Light refreshments will be provided. For more information, contact Esther McGinnis at 701-231-7406.
Oak leaf blister - (Taphrina caerulescens)
Host(s): Bur and other oaks
Description/Biology: Fungal spores infect new leaves as buds begin to open in spring. Following infection, the fungus grows intercellular within the leaf tissue, causing leaf deformities termed blisters to form. Under favorable conditions, these blisters may continue to expand as new leaf tissue is invaded by the fungus. New leaves that are formed in mid-summer may also be infected, causing a second cycle of this disease. The spore-bearing structures of this fungus are produced on the lower surface of blisters and can only be seen with a microscope. The fungus overwinters on bud scales and in bark crevices.
Damage/Symptoms: This disease often goes unnoticed except during occasional moist years or localities that favor heavy infections. Leaf blisters appear as wrinkled, distinctly raised bulges on the upper leaf surface and are lighter in color compared to non-infected portions of the leaf. The tissue on the upper surface of the blister may stay green for several weeks before desiccating and turning brown, while the lower leaf surface may appear gray. Typically blisters are 3 to 20 mm across but may coalesce and encompass the entire leaf. Often, severely blistered leaves may curl and fall from the tree prematurely. These disease symptoms are more prominent in the lower, more shaded portions of the crown. Bur oak is a hardy, resilient species and this particular foliar disease rarely causes substantial physical damage. Despite this, oak leaf blister can cause stress to young trees, trees that have been severely infected for several consecutive years, or newly transplanted trees. It can cause aesthetic damage, but this is infrequent, except where the tree’s genotype and local environmental conditions are particularly favorable for the disease.
Comments: Cultural practices such as proper watering and mulching may increase the tree’s vigor and may sufficiently minimize the damage caused by this pathogen. High-value ornamental trees may benefit from chemical control in areas of high disease pressure. Protectant fungicides must be applied prior to and during bud break to prevent infection. Fungicides are not effective once leaves begin to expand because infection has already occurred. Various formulations of chlorothalonil and mancozeb are registered for this disease. Some authors also recommend either lime sulfur at a rate of 10 tablespoons per gallon, or Bordeaux mix. Removal of infected leaves has not been shown to effectively reduce disease development. (Information provided by Joe Zeleznik submitted by Jackie Buckley)
I had a sample of ash rust brought to my office by a Morton County client, a common disease of ash trees. This fungus is often noticed as small patches of orange lesions on the leaves. Sometimes the disease attacks the petiole or twig, occurring as a large misshapen mass. The lesions contain two types of disease spores. If the infection is severe enough, leaves will fall off the tree prematurely.
Like many other rust diseases, ash rust has two hosts – ash trees and several cordgrass (Spartina) species. The disease is most serious near areas where the cordgrass is abundant, such as wet or saline soils. There are several types of rust diseases on cordgrass and they are difficult to distinguish from one another. Therefore, the presence of rust on cordgrass does not necessarily mean that ash trees in the area are threatened.
Most infection occurs in the spring, but new infections can still occur in early summer if conditions are right – wet weather with warm temperatures, about 55 to 75 F. The best way to control ash rust is to eliminate nearby cordgrass. If this is not possible, fungicides that contain the active ingredient myclobutanil may be used as a protectant fungicide on the trees whenever conditions for severe infection are high. (Submitted by Jackie Buckley Morton County Extension Agent)