June 20, 2005

This week brought pleasant relief from the hot temperatures we were 

experiencing earlier in the month. Unfortunately the break in the 

weather was not preceded by any significant rainfall. And by the time 

this article is printed the temperature will most likely be back to 90. 

Keeping the garden sufficiently watered seems to be the main garden 

chore so far this season.

Landscape plants can get by without fertilizing, in fact it is best not 

to feed plants under drought stress, but they do not cope well without 

water. Drooping, shriveled and browned leaves as well as leaf drop are 

all signals of drought stress. Pay particular attention to plants 

exhibiting these signs.

Eliminate weeds; they compete with the garden plantings for the 

available moisture. Cover bare patches around the garden with mulch to 

reduce water loss from evaporation. Irrigate the area before laying 

down 

the mulch. Keep the mulch layer just 2-3 inches deep so that rainfall 

and irrigation can still trickle through to the root zone.

Container plants need to be watered at least every other day at this 

point in the growing season. Hanging baskets in full sun all day should 

be checked daily. When the temperature hits the 90-degree mark, check 

all potted plants daily. Sometimes you miss watering a potted plant and 

the soil becomes so dry that water runs right through without 

re-hydrating the plant. The soil loses so much moisture content that it 

shrinks away from the sides of the pot.

When this happens immerse the container and its contents into a large 

bucket or tub of water and let it soak. Once the soil has completely 

moistened remove the planter from the soak and set it in a shady spot 

to 

recover. Most plants will perk up in an hour or two. Letting a plant 

get 

that dry multiple times will result in a weakened plant that grows 

poorly the rest of the season.

Plants under drought stress are targets for insect attack. Keep an eye 

out for caterpillars, beetles and mites. Using a stream of water from 

the hose, an application of insecticidal soap or simple handpicking can 

treat many insect pests.

One insect that has been troublesome over the past couple of summers is 

the bagworm. This insect usually goes unnoticed until the telltale bags 

appear hanging from the branches of arborvitae, spruce or juniper. Once 

the insect has formed its protective bag it can’t be treated with 

insecticides. At that point, removing the bags by hand is the only 

treatment. In June the small larvae are discreetly feeding on the 

leaves. Spray now to control bagworm on previously infested plants.

Hot dry weather is favorable for spider mites on landscape plants. 

Dwarf 

Alberta spruce, juniper, blue spruce, azalea, rhododendrons and 

andromeda all are susceptible to spider mite damage. Spider mites are 

very small, usually resembling specks of black pepper. Fine webbing may 

be visible when the plant is infested. The damage to the leaf will 

appear as white spots when examined closely. Later on entire patches of 

the tree or shrub will turn brown. To prevent spider mites periodically 

hose the host plants with water to dislodge the pests.

Many spring blooming shrubs that have finished blooming can be trimmed 

now. Azaleas can be pruned or shaped. The finished flower clusters on 

rhododendrons should be pinched off. Take care not to damage the new 

leaf buds located just under the old flower cluster. Lilacs can be 

trimmed or thinned and try to remove all the finished blooms.

Roses need to be deadheaded regularly, especially after the first flush 

of flowers. Cut the stem just above an outward facing leaf that has 

five 

leaflets. The bud at the base of the leaf will grow to produce more 

flowers. Most of today’s newer roses have been bred to be repeat 

bloomers. They will also benefit from an application of fertilizer 

after 

the first flush of blooms.

Perennials and many summer annuals will bloom longer or even 

continuously if they are deadheaded. Salvias, daylilies, coreopsis and 

coneflowers all repeat blooming with frequent removal of the spent 

flowers. Summer blooming spireas, catmints and many varieties of yarrow 

will bloom a second time later in the summer if they are pruned after 

the first bloom period is finished.

Beth Nardone, botanist, is a resident of Hillsborough and is the 

Nursery 

Manager at the Belle Mead Co-Op. Questions and comments can be sent to 

bethtanical@patmedia.net