New Guinea Impatiens and how to grow

My New Guinea impatience plant was huge and hardy with many flowers and buds. It was dry when I bought it so I watered it as soon as I got home. The next day it was wilty so I gave it some water soluble fertilizer and within an hour it perked up and was beautiful. Within 2 days it was badly wilted (I think my cat tried eating some of it)

So I moved it outside where the cat couldn’t get at it. Now it’s been a week and it’s almost dead. It has early sun, then some shade. It’s in bad shape. I had 2 plants last year that thrived. Help.

— Sharon

Wilting New Guinea impatiens can usually be traced to three causes: Overwatering, under watering and heat stress. Sharon seems to have encountered at least two of the three. The best situation is for evenly moist soil without water extremes. These watering problems can then cause other problems, more fatal ones as they create ideal conditions for fungal and bacterial problems.

These disease agents, spores, and bacteria, are present in the soil, This is one of the reasons fresh, sterile soil is always recommended in containers. The other is that fresh potting mix drains well, allowing the soil to drain excess water.

Stem rot: is caused by several different fungi; all live in the soil, The fungus girdles the stem causing the growth above to wilt and die. It is more prevalent in heavy soil that remains wet after watering. Bacterial wilt has a similar effect on the plant and can be distinguished by a yellow ooze inside affected stems.

Mulching would normally be a good solution as it would limit the number of spores splashed onto the plant during watering or rainfall. However, the mulch will also retain moisture in the soil, allowing the fungus to spread/, Mulch should not be placed against or near where the stems emerge from the soil.

Sadly the answer is that once affected by wilt or rot there is little to do but clear out the damaged material, keep the soil moist not wet, and allow the surface of the soil to dry slightly between waterings. Generally, the plants will not survive. Next year, be sure the pots are sterile, the potting mix fresh, the container has ample drainage and watering is regular but not excessive. Do not allow the pots to sit in water. Remove infected plants and discard in the trash as the problem can quickly spread to all nearby impatiens.

We have a question regarding our Norfolk Island Pine (fondly called Bob). About a year or so ago we transplanted it due to the fact that it was pot-bound and starting to become top-heavy. Since that time we have noticed some bugs (which we think are fungus gnats) crawling around the roots in the top portion of the pot. We tried yellow sticky traps, which didn’t work, and then read somewhere to try quartered raw potatoes which we placed in the pot in the morning and disposed of the next morning. These potatoes were loaded with these crawling bugs. Although this seems to have helped somewhat, it has not eliminated all the bugs and just seems tedious to continue. We don’t think we should transplant Bob again because we have read that Norfolk Island Pines do not like to be transplanted or moved. Do you have any advice on how to get rid of the bugs? Thank you!

— Arndt Family

If you have fungus gnats, you should see tiny fly-like insects around the plant, I suggest the following:

Don’t overwater and be sure to drain any saucer or tray under the tree.

Cover the surface of the soil with a layer of gravel or small stones to keep the adult gnats from accessing the soil to lay eggs.

Consider using a product specifically labeled for fungus gnats and apply as a soil drench according to the manufacturer’s instructions.

I potted up a red mandevilla this week, adding an old pyramidal trellis for support, It is already twining up the trellis and has multiple open blooms. Although I rarely winter over these plants, they are well worth the price for summer color. Larger plants can be quite pricey so I generally go for the six or eight-inch pot and transplant into a larger fancy container.

There is another pot with three lantana plants set on the deck railing. It has quickly become a favorite with the butterflies and the occasional hummingbird.

My new oak leaf hydrangea, Ruby Slipper, is healthy but a bit small so it will just get a larger pot this year and maybe move into the garden in a year or two.

Sue Kittek is also a freelance garden columnist, writer, and lecturer. Send questions to Garden Keeper at grdnkpr@gmail.com or mail: Garden Keeper, The Morning Call, PO Box 1260, Allentown, PA 18105.

Planting: Plant a second crop of snap or pole beans, radishes, carrots. Sow small sections of crops like beans, radishes, lettuce, and spinach at regular intervals to create a longer harvest. Set out tomatoes, basil, eggplant and pepper transplants as the weather and soil warms. Start seed for baby’s breath, cosmos, zinnias, salsify, eggplant, summer squash and winter squash. Direct sow corn, okra, and rutabaga. Continue sowing snap, bush and pole beans, cantaloupe, melons, cucumbers, rhubarb, summer and winter squash. Plant or pot up summer bulbs and tubers such as dahlias, cannas, calla lilies, and caladiums. Plant bare-root trees and shrubs. Make sure the soil is dry enough to work — Don’t dig or plant in mud. Buy annuals for containers, annual garden beds and to fill in bare spots in perennial or shrub beds.

Seasonal: Cut back boltonia by half the size of the plant. Cut Joe-pye weed back to three feet tall. Cut back candy tuft to encourage bushiness. Shear back woodland phlox (P. divaricata)

Deadhead sea thrift (Armeria), centaurea, centranthus ruber, dianthus, fringed bleeding heart (Dicentra exima), hardy geraniums, bearded irises, red-hot poker (Kniphofia uvaria/tritoma), catmint (Nepeta), herbaceous peonies, Oriental poppies, pincushion flowers (Scabiosa).

Fertilize Siberian irises, summer phlox (P. paniculata) and Shasta daisies with a light application of balanced fertilizer

Divide spring-blooming perennials after they finish blooming. Cut back peony flower stems as the blooms fade. Allow the greens to grow until fall, then cut them back to the ground. Clip back iris flower stems as the blooms fade; divide plants in crowded beds Start pinching back chrysanthemums and asters to promote bushy growth and more flowers. Continue to pinch back new tips at two-week intervals until early July. Ease out your plants that wintered over inside. Start with an hour or so on a warm day and increase outdoor time until the nights are regularly in the 50°F range before leaving them out for the season.

Visit nurseries as they open for inspiration as well as new plants. Shop for summer bulbs as well. Apply a top dressing of compost to lawns and beds. Test soil for new beds, Retest soil in poorly performing areas or those that haven’t been tested in the last 3-5 years. Cut back ornamental grasses. Divide when you see new green growth. Divide hostas and daylilies.

Prune and divide perennials that bloom in late summer or fall. Prune back and clear out dead, diseased or unattractive stems from perennials and shrubs, but not those that flower in the spring. Please check proper pruning information for each plant and prune as needed and recommended. Apply spring and summer mulch, two to three inches deep and placed a few inches away from foundations, tree trunks and other plants. Fluff mulch and add more if necessary. Apply corn gluten based weed control in the garden and establish a schedule for reapplication, usually at four to six week intervals

Lawn: Keep newly seeded or sodded lawns watered; supplement rain in weeks where less than an inch. By mid-June, apply spring fertilizer treatments. Apply preemergent crabgrass control in the next few weeks. Fill in holes and low spots in lawn.

Chores: Water any recent plantings anytime the ground isn’t frozen and we experience a week with less than an inch of rain. Fix damaged screens and garden hoses. Note damaged caulking around doors and windows. Dump standing water and remove anything that may collect rainwater to help control mosquito populations. Provide deer, rabbit and groundhog protection for vulnerable plants. Reapply taste or scent deterrents. Clean and fill bird feeders regularly. Clean up spilled seed and empty hulls. Dump, scrub and refill birdbaths at least once a week. Consider setting out nesting materials if you have them.

Clear gutters and direct rainwater runoff away from house foundations. Tools, equipment, and supplies: Store winter equipment and replace or repair as needed.

Check spring/summer equipment — repair or replace damaged or worn out tools. Check power tools and mowers and send for service if needed.

Security: Clear lawns of debris before mowing and make sure pets, children and others are well away from the area being mowed.

Store garden chemicals indoors away from pets and children. Discard outdated ones at local chemical collection events. Photograph storm damage before clearing or repairing for insurance claims and file promptly. Anytime you are outside and the temperatures are about 50°F or warmer watch for tick bites. Use an insect repellent containing Deet on the skin. Apply a permethrin product to clothing.

Wear light-colored clothing, long sleeves, hats and long pants when working in the garden. Stay hydrated. Drink water or other non-caffeinated, nonalcoholic beverages. Even in cold weather, apply sunscreen, wear hats and limit exposure to the sun. Wear closed-toe shoes and gloves; use eye protection; and use ear protection when using any loud power tools.