May Yard and Garden Tips
Watch out for:
- Japanese beetles - these pests will defoliate plants in short order. Keep a sharp lookout for them. If you find an infestation use carbaryl (Sevin, etc.), which is very effective. Observe all label precautions on mixing and use. Do not use dusts due to the
problem with application - a spray made using the liquid form of the product
will work fine. See
Japanese Beetle for more information.
- Fireblight - inspect fruit trees for fireblight. If you had problems with
fireblight last year, you will need to spray your blooms this year to
prevent the spread. The best defense is a fireblight-resistant
Fireblight for more information.
- Lawn diseases - it's time to begin watching for problems
with brown patch and dollar spot in warm season grasses, especially if
you had problems with one of them last year. See Brown Patch Disease of Lawns and Leaf Diseases of Lawns for more information.
- Chinch bugs - watch for chinch bugs in your warm season lawn. See Chinch Bugs for more information.
- White grubs - the bacteria Bacillus thuringiensis does a
nice job on them, but it does take a little time to build up in the
soil. See White Grub Management in Turfgrass for more information.
- Bag worms - bag worms can kill a tree if it is heavily infested. Inspect your trees periodically - bagworms seem to like juniper, arborvitae, and pines, but they are will attack many broadleaf shrubs and trees such as rose, sycamore, maple, elm, and black locust.. Hand-picking light infestations works well; applying the bacteria Bacillus thuringiensis will also take care of the problem. See
Bagworms for more information.
- Oakworms -
oakworms and canker worms may appear in the spring and defoliate oak
trees. This will not kill the trees, but
it will add some stress to them. The trees will develop more leaves. The chemical carbaryl (Sevin, etc.) will kill
the worms, but treatment of a large tree is not practical nor safe and therefore is not
recommended. However, if you have a
small oak tree (less than 7 feet tall) infested with them that can be safely
sprayed, an application of this insecticide will control them.
- Garden insects - keep an eye out for corn earworm, cucumber beetle, and squash vine borer in the garden. See Insect Pests of Sweet Corn and Cucumber, Squash, Melon & Other Cucurbit Insect Pests for more information.
- Blossom end rot - check your tomatoes for blossom end rot
on the fruit as it begins to form. This is usually an indication of a
calcium deficiency. Place a handful of gypsum (land plaster) in the
soil beside the tomato at planting (or later) to prevent this. Foliar
sprays such as blossom end rot spray will also help alleviate the
problem. Nothing will "heal" the fruit with rot on it, so remove and discard them. See Tomato for more information.
Things to do:
- Bulbs - you should be planting your summer- and fall-flowering bulbs in April and May, such
as dahlias, gladioli , cannas, and lilies. Be sure to plant after the soil temperature reaches 55 degrees F. See
Summer- and Fall-Flowering Bulbs for more information
- Spray fruit trees - continue spraying your fruit
trees with a fungicide (Captan, etc.) every 7 to 10 days to provide the
beautiful fruit you look forward to. Do not use any insecticides on
the trees until less than 10% of the blooms remain - you certainly do
not want to hurt your bee pollinators. The fungicide will have no
effect on them.
- Lawn Fertilizer - you should apply a complete fertilizer to your warm season lawn this month. See Fertilizing Lawns for more information.
- Fire ants - if you broadcast baits, apply your first
treatment during the last week of April or the first week few weeks of May. Be sure to apply fresh
bait, and do it at the correct time of day (fire ants only forage
actively when the ground temperature is between 70 and 95 degrees F). See the
Fire Ant Management in the Home Lawn and the
State Fire Ant website for more information.
- Lawn Aeration - any time your warm season lawn is actively growing is a good time to aerate. David Parker relates that you should "aerate as long as you can stand it, then go over the yard once more." See Aerating Lawns for more information.
- Lawn Establishment - if you plan to plant a warm-season
(centipede, zoysia, Bermuda, St. Augustine) lawn, the best time to
plant is in the spring and summer. If you are planting Bermuda by
seed, use the hulled seed at this time of year (you can seed with
unhulled seed in the fall). Wait until next fall for cool-season
grasses (fescue). See Lawn Establishment for more information.
- Nutsedge or "nutgrass" - nutsedge is very difficult to
control. There are two main types in our area - purple and yellow.
You must identify which you have before you begin treatment.
Herbicides must be applied when the nutsedge is actively growing, which
means decent soil moisture and warm conditions. See
Nutsedge for more information.
- Irrigation - you may be irrigating late this month if we have a dry spring. See
the Home and Garden Center's irrigation publications for more information, espcecially the publication on Irrigation Time of Day.
Spring and fall are good times for disease to blossom, so do not allow
your irrigation scheduling to increase these problems. One inch per
week is the appropriate amount for most lawns and vegetables (except
sweet corn and yellow squash, which may require up to two inches
depending on growth stage). Include rainfall in this amount, and see How Much Water to determine how much water you are actually applying, and Determining When to Irrigate to help determine when your plants need water. Do not irrigate every day! There are a few exceptions to this rule (such as potted plants), but only a few.
- Vegetables - Some planting times for more common vegetables (See Planning a Garden for a full list and planting depths and spacings):
- Cucumbers - Apr. 15 - May 15
- Cantaloupes - Apr. 15 - May 15
- Lima beans - May 1 - 15
- Melons - Apr. 20 - Jun. 30
- Okra - May 1 - 15
- Peppers - May 1 - 30
- Southern peas - May 1 - June 30
- Sweet potato - May 10 - June 10
- Squash - Apr. 15 - May 15
- Tomato - May 1-30
For more information for May, see
This Month in Your Garden's