Best of Horticultural Tips for July
Trees & Shrubs
- Remove faded flowers from annuals to encourage more flowers.
- Deadhead perennials to avoid unwanted “volunteers” and to direct the plant’s energy toward its own growth.
- Rainy weather can cause problems for iris. They do not like wet feet. Be on the lookout for iris leaf-spot. See http://extensionpubs.unl.edu/publication/9000016364823/culture-of-iris/ for ways to recognize and treat these problems. It is also time to thin out iris to avoid future problems.
- Until the end of the month, continue to pinch mums to promote bushier plants.
- Tall asters may be trimmed back until the middle of the month to prevent the plants from falling over when they are in full bloom.
- During periods of extreme heat, containers may need to be watered every day. Arrange for a “pot sitter” if you are going on vacation.
- Be sure to treat for sod webworms if you have had problems in the past. Check out how to recognize symptoms and how to treat by referring to https://entomology.unl.edu/turfent/documnts/swebwrms.shtml
- Soap solutions irritate the body of the insect. Try using insecticidal soap or make your own to deal with a pest. Just make sure the pest is accurately identified first.
- Bulbs may be soaked in water overnight before planting. The soaked bulbs will have a head start and should bloom first.
- Asiatic lilies should be divided every 2 to 3 years; dig early in fall.
- Perennials and shrubs don’t need a lot of fertilizer. Use a slow-release fertilizer or good compost. Remember that when using organic mulch, such as grass clippings, wood chips or wood mulch, you are improving the soil a little each year. As the mulch decomposes, it is feeding the plants.
- “Full Sun to Part Shade” means that a plant prefers the sunnier side. “Part Shade to Part Sun” means the shadier location is better.
- Signs of lack of light in a plant include long, leggy growth, pale green color, and weak and floppy stems. Use the “right plant right place” guideline. If a plant is not thriving, research its ideal location and then move it someplace appropriate in the garden. Just remember to water carefully by hand until the transplant is established.
- This is the month to order fall bulbs.
- July is the time for mid-late daylily bloomers.
- Chicory flowering is at its peak, with the blue-violet blooms commonly seen along roadsides.
- Remove foliage from spring flowering bulbs after it fades.
- Dig, divide and replant irises.
- Ornamentals add contrast that provides a break from the many fine features of flowers and foliage.
- Tiger Eye Sumac isn’t invasive, but it does send out suckers—cut back in spring.
- Big leaf hydrangea flowers from top to bottom—it works well at the front of a border.
- Sessile means “stalkless, referring to the flower which sits neatly on the foliage like “something sumptuous being served on a plate.”
- Apply sunscreen generously before going outdoors. It takes approximately 15 minutes for your skin to absorb the sunscreen and protect you. If you wait until you are in the sun to apply sunscreen, your skin is actually unprotected and can burn. To remain protected, reapply every two hours.
- Now is the time to be thinking about seeding or reseeding your lawn. Buy your seed, but do not seed until at least August 15. Be ready. Quality seed offers a greater chance of a quality lawn. If you buy cheap seed, you may be planting weed seeds along with grass seed! Read the package.
- Kentucky Bluegrass has the poorest shade tolerance among turfgrasses planted in the Midwest and usually performs poorly under trees. Instead of fighting this fact, try a shade-loving groundcover. Lamium (Dead Nettle) grows well under trees. Its predominately white leaves lighten up the area. And different varieties bloom in white, pink, or purple for months.
- Remember to mow high (3 – 4 inches) during hot weather. Mowing lower will stress the grass out, leaving it to go dormant and encourage the growth of weeds.
- Water deeply and less often to promote healthy grass roots.
- Watch for summer disease of turf.
Trees & Shrubs
- The average lifespan of a street tree is about 13 years. Do not kill a tree by mounding mulch up around the trunk or building a raised bed around it. Tree roots need oxygen. Smothering the tree with mulch or a raised bed results in a slow but certain death.
- Thin an overgrown weigela by cutting one-third of the largest branches close to the ground after the shrub is done blooming. This method also works for lilacs and viburnams.
- The bright pinks and vibrant reds of a Weigela can be spotted by hummingbirds up to one- half mile away.
- When river birch have yellow appearance that indicates an iron deficiency. Iron can’t be taken up by the tree if the soil PH is too high.
- Emerald Ash borer is here, but do not jump to conclusions. Check with a professional arborist that can provide you with creditable information. Before taking any action, check with at least two.
- This is the month to check for bagworms.
- Remove suckers and water sprouts from trees.