June Gardening Tips for Oklahoma – Daily Ardmoreite


Pat Neasbitt Master Gardener

June is such an amazing month in the Oklahoma garden. Everything grows, including lots of weeds. The following tips will help you ensure that your garden is beautiful and healthy.

General landscape

• Mulch ornamentals, vegetables and annuals to reduce soil crusting, regulate temperatures and slow moisture loss during hot summer temperatures and drying winds. Mulching will reduce summer yard maintenance by up to 80 percent. This means more time to enjoy your garden instead of just working on it.

· Control aphids on crape myrtles and spider mites on tomatoes with a strong stream of water from the hose. Be sure to get under the leaves where they are trailing. Spider mite damage can be seen as foliage that turns pale and mottled. Shake a branch on a piece of white paper and watch for tiny red dots moving around.

• Watch for the first generation of fall moths and remove the webs with a long stick or pruner to break the web and expose the worms for the birds to tend to.


• Fertilize warm season grasses, if necessary, at the rate of 1 lb of nitrogen per 1000 square feet. Do not fertilize fescue and other cool season grasses during the summer.

• Seeding of warm season grasses should be completed by the end of June (until July for improved varieties such as Riviera and Yukon) to reduce winter losses. The OSU fact sheet (HLA-6419) will provide detailed information on sowing grass.

• Those disgusting white grubs you find while rummaging through your garden are future beetles. They eat the roots of plants, including lawn grasses. I throw them on the floor or put them on the feeder for a tasty treat for the birds. Beetles are attracted to lights at night, so turn off all outside lights, if possible.

Fruits and nuts

• Renovate overgrown strawberry beds after the last harvest. Start by setting your lawnmower to its highest setting and mow the foliage. Then thin crowns spaced 12 to 24 inches apart. Apply recommended fertilizer and keep watered. OSU Fact Sheet (HLA-6214)

Trees and Shrubs

• Strong and unwanted branches should be removed or shortened on newly planted trees. Watch for forks in the main trunk and remove the less desirable trunk as soon as it is noticed. OSU Fact Sheet (HLA-6415)

• If you are treating pines for pine needle disease, it is time for another treatment.

• Remove tree wraps during the summer to avoid potential disease and insect buildup. Leave lower branches on young trees to protect against sunburn and to speed trunk growth. Plastic, perforated, and stretchy tree wraps are the only ones that should ever be used from March through November, and they can help somewhat protect young trees from damage from lawnmowers and weed eaters.

• Don’t make “mulch volcanoes” around your trees. They defeat the purpose of applying mulch because the water will run off the roots instead of being directed towards them. Mulch built up against the trunk will invite disease and insects and can kill your trees. It is an excellent home for mice that nibble the bark; and it looks really silly, especially if the fake dyed red mulch is used – it looks like giant red anthills.

• Softwood cuttings from new growth of many shrubs will root if propagated in a moist, shady location.

• Rose Rosette Disease (RRD) is a virus spread by the tiny eriophyid mite. Signs of Rose Rosette are disfigured bright red new growth (different from normal red new growth), rapidly elongated stems, and witches’ brooms, which are sections of multiple red stems with deformed leaves covered with a large number of thorns. Currently, there is no known cure for this disease other than digging up and destroying the entire plant. If it only affects one branch, you can try cutting it past the deformed area and throwing it in a plastic trash bag. Be sure to rake up all dead leaves and debris from under the roses. The easiest way to prevent the disease from spreading is to plant roses in different areas of the landscape instead of grouping them in one area or planting them in a hedge. Monoculture, consisting of many plants together of the same species, is an invitation to disease and insect damage.


• Remove the flower stalks from coleus, caladiums, lamb’s ear and basil before the buds open. This will promote the growth of new leaves.

• Indoor plants can be moved outdoors this month. Sink the pots in a cool, shaded garden bed to prevent them from drying out too quickly.

• Water container plants and hanging baskets often. Monthly fertilizing with seaweed extract, fish emulsion or compost tea will keep them flowering. A time-release fertilizer is also useful for container plantings.

• When cutting fresh roses or removing spent roses, cut them into leaflets facing away from the bush to promote open growth, good air circulation and continuous flowering. Deadhead for continuous flowering.

• Top annuals and perennials to keep them blooming well into the fall.

· Dig up, divide and replant spring bulbs that have become too numerous.

• During the summer, soil moisture is essential for good crop production. The best way to retain moisture is mulching. A good mulch not only retains valuable moisture needed for plant growth, but also improves overall gardening success. Mulches work best if they are 3 to 4 inches deep, depending on the material used. Happy gardening!


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