May is the ideal month to plant the heat-lovers--the
vegetables and flowers that seem to thrive and bloom more
lustily when the weather's hot and sunny. Earlier in spring
and later in fall, we coddle them to stretch the seasons,
but now is when they grow really fast. Other plants may tolerate
our summers, flourishing in spring and fall; but these plants
relish the heat and bright light. Just keep them well- mulched
and watered, and they'll produce exuberantly.


Thornless boysenberries enable painless
harvesting of succulent treats.
Photo by Yvonne Savio,
© UC Regents, 2000. |
Sow seeds of lima and snap beans, beets, carrots,
celery, chard, chic-ory, chives, corn, cucumbers, eggplants,
leeks, warm-season lettuces, melons, okras, green onions,
peanuts, peppers, pumpkins, soybeans, warm-season spinaches,
squashes, sweet potatoes, and tomatoes.
Use legume innoculant with the beans for better
germination as you did earlier with peas. Sprinkle a bit in
the hole or furrow, place the bean on top, cover with soil,
and water it all in.
If you plan to preserve some of your garden's
bounty, you may prefer to grow vegetable varieties which will
be ready for harvest all at one time. On the other hand, you
may prefer processing several small batches rather than making
a marathon effort. In this case, reseed or transplant seedlings
every two or three weeks for continuous harvests.
Interplant cucumbers and beans to repel cucumbers
beetles and prevent the wilt diseases they carry. Also plant
Cucurbita lagenaria gourds as trap plants for cucumber
beetles. Plant potatoes to repel squash bugs.
Plant corn in blocks of at least four rows
in each direction to assure good pollination. Make succession
plantings through the end of June only, as later plantings
generally suffer from severe smut problems when they mature
in September.
Corn stalks make convenient pole bean supports.
Plant the beans after the corn is six inches tall, no sooner,
or the beans will outgrow the corn.
When hand-picking those hard-to-see tomato
hornworms, sprinkle the plants lightly with water first. Then,
as the horn-worms wiggle to shake off the water, you can easily
see them and remove them.
Take no harvests this year from the asparagus,
artichokes, and rhubarb that you planted this spring. Let
the plant use all its energy to develop a good root system,
instead of expending it sending up more shoots.
Trellises provide support for greater fruit
production per square foot of soil and for longer periods
because more leaf area is exposed to sunlight for more photosynthesis,
and more air circu-lation means less fruit rot and ground-insect
attack. Vines spreading on a trellis provide shade for a porch,
patio, or wall. Crops grown on a trellis are easier to pick
and cleaner, not available to snails and slugs, and not prone
to ground rot.
Some vines need more guidance and anchoring
onto the trellis than others, but all will grow well with
proper fertilization and irrigation. Clamp clothes pins attached
to twine on each side of a vine for easy adjustment as the
vine grows.
Support heavy fruits on shelving, in netting,
or with rags or old nylons. If left unsupported, their weight
will drag the vines down from the trellis. When weeds are
pulled up from beneath trellised vines, there is less injury
to the cultivated plants because of vines and fruits shoved
out of the way.
When foliage on garlic, bulb onions, and shallots
begins to dry naturally later this month, stop irrigating.
This will encourage the dry outer layers to form on the bulbs--necessary
for long storage. When about half of the foliage slumps to
the ground naturally, bend the rest to initiate this maturing.
The bulbs will be ready for harvest when the foliage is thoroughly
dry and crisp.

Bintje potatoes are one of many heirloom and rediscovered
favorites for home gardens. Photo by Yvonne Savio, ©
UC Regents, 2000. |
When removing spent pea vines, cut them off
at the soil level rather than pulling them out. The roots
should have nodules that contain excess nitrogen from their
fixation process, and this nitrogen is released into the soil
as the roots decompose, available for the next crop's roots.
Fertilize strawberries with a balanced fertilizer
now and after each heavy fruit-bearing period for continued
strong growth and fruit set. A seaweed and fish emulsion solution
offers many micronutrients. Avoid mulching with manure, however,
as strawberries are not tolerant of salt, and manure (especially
chicken) has a relatively high level. Even with excellent
irrigation and drainage, summer heat will cause this saltiness
to burn the berry plants.
Plant citrus and other tender trees. Keep the
soil well mulched to hold in moisture with fewer waterings.
Too little water results in stunted growth and reduced fruiting.
Fruit tree "suckers" (growing from
the base of the plant or tree) or "watersprouts"
(growing straight up from a branch) compete for water and
nutrients but bear no flowers or fruit. On citrus, these wayward
shoots have long thorns and leaves that look different from
those on "regular" branches. Yank them out or roughly
cut or smash them to discourage regrowth. It's nice to know
that the rootstock is so healthy, but you want the energy
to go into the flowers and fruit.
Feed fruit trees, now that they're actively
growing. They'll provide a good leaf canopy with these additional
nutrients.
Paint tree trunks with light-colored indoor
latex paint to prevent sunburn damage. Use an inexpensive
brand, or thin down an expensive one to half paint and half
water.
Thin grape bunches and marble-sized tree fruits
for superior fruit quality. Tree branches or vines may break
if too much fruit is left on them. Remove about half of the
number of grape clusters--more on young vines. Thin tree fruits
on alternate sides of branches for balance. The minimum distance
to leave fruits on branches is determined by the age of the
tree and the size of the mature fruit. Five to eight inches
for apples, pears, peaches, and nectarines; four inches for
plums and apricots. In general, leave on the tree or vine
only what you will realistically use. Thin too much rather
than not enough so trees and vines aren't strained. Nut trees
will usually take care of their own thinning.
Renew mulches under grapes and berries. Strawberries
and blueberries benefit from loose, acid mulches such as pine
needles or rotted sawdust. Raspberries and blackberries prefer
a hay or straw mulch.
Carefully collect and destroy all leaves
affected by peach-leaf curl or other diseases. Do not compost
these leaves or use them as mulch, as this will spread the diseases.


Sierra Madre's historic wisteria, planted in the 1880s,
blooms profusely and covers two houses and their yards.
Photo by Yvonne Savio,
© UC Regents, 2000. |
Sow or transplant ageratums, alyssums, globe
amaranths, asters, baby's breath, bachelor's buttons, balsam,
fibrous begonias, bougainvilleas, calendula, campanula (bellflower,
canterbury bells), candytufts, carnations, celosias (cockscomb),
chrysanthemum, clarkia (godetia), cleome, coleus, columbines,
coral bells, coreopsis, cosmos, English daisy, gloriosa daisy,
marguerite and Shasta daisies, dahlias, delphiniums, dianthus
(pinks, sweet william), forget-me-nots, four-o'clocks, foxgloves,
gaillardias, gazanias, gerberas (transvaal daisy), geums, geraniums,
hollyhocks, hosta (plantain lily), impatiens, lantanas, larkspurs,
linaria, lobelias, lunaria (honesty, money, and silver dollar
plant), marigolds, morning glories, nasturtiums, nicotianas,
pansies, penstemons, periwinkle (vinca), petunias, phlox, California
and Oriental and Shirley pop-pies, portulacas (moss or sun rose),
potentilla (cinquefoil), primroses (primula), pyrethrums (painted
daisy, painted lady), rosemary, salpiglossis, salvias, scabiosas
(pincushion flower), snapdragons, statice (sea lavender and
other colors), stock, strawflowers, sunflowers, sweet peas,
tithonias (Mexican sunflower), verbenas, vinca, violas, and
zinnias.
Blooming plants can brighten shady garden areas
and provide lush foliage during hot summers. In dense to medium
shade, plant begonias, coleus, and impatiens. In light shade
with partial sun, plant ageratum, canterbury bells, lobelia,
nicotiana, and salvias.
Blooming shrubs that need little water when
they're mature include abelia, bottlebrush, broom, ceanothus,
cotoneaster, crape myrtle, grevillea, oleander, pittosporum,
pyracantha, raphiolepis, rockrose (cistus), and strawberry
bush.
For fragrance, plant citrus, gardenia, jasmine,
mock orange, and roses.
Start tuberous begonia bulbs in a sandy compost
mixture in filtered sun, and keep them well-watered from the
bottom. Other bulb-type plants to start include amaryllis,
caladium, calla lily, canna lily, dahlia, gladiolus, tigridia,
tuberose, and watsonia.
Plant cactus, succulents, and palms. Water
to settle them in well, but allow the soil to dry out between
future waterings.
Remove faded blooms and seedpods from spring-blooming
bulbs, but leave the foliage on until it dies back naturally.
Apply a balanced fertilizer for next year's strong growth
and bloom. When the foliage has died back completely, dig
the bulbs up, gently remove any soil (but don't wash them),
and store them in a cool, dry, well-aerated area.
Prune tips of azaleas, carnations, chrysanthemums,
fuchsias, geraniums, impatiens, lavender, marguerites, marigolds,
petun-ias, rhododen-drons, rosemary, sedums and zinnias to
gently shape the plants and encourage them to bush out. Root
these cuttings. Don't allow coleus plants to flower--the blooms
are insignifi-cant, and the colorful foliage becomes skimpy.
Cut back spring-blooming shrubs and vines,
including clematis and wisteria, to shape them and promote
flowering wood development for next year.
For bushier mums with lots of blooms this fall,
pinch back stems after each six inches of growth. Continue
pinching until July, then let growth develop naturally, staking
as desired.
Mow lawns once or twice a week. Set mower blade
height to between two and three inches. Don't cut off more
than 25 percent of new growth at a time, or the lawn won't
have enough "green part" to grow well.
Keep the lawn fertilized with a slow-release
fertilizer just enough to grow well but not so much it stimulates
lots of lush, water-demanding growth that'll keep you mowing!
Begin to change lawn watering patterns from
every several days to only once a week or ten days. Let the
grass tell you when it needs to be watered--it'll wilt slightly
and turn from bright green to dull green. Continue to water
deeply to thoroughly moisten the soil down to the bottom root
tips (6 to 12 inches deep). This will allow the surface of
the soil to dry between waterings and encourage deep rooting,
so the lawns are healthier and can go longer between waterings.
Diseases develop when grass blades and the soil surface are
constantly wet, especially when the weather's warm.
Weekly or so until fall, prune the spent blooms
on roses down to the first five-part leaf or a bit further
to gently shape the plant; then feed it lightly, and water.
Also, prune out shoots from the rootstocks below the grafts
and twiggy growth, especially in the center of the plant,
for better air circulation. Water only in the mornings, so
water on the foliage will dry before sunset--lessening mildew
and other disease problems.
Maintain a good mulch of organic matter covering garden soil
throughout the summer. This prevents crusting and cracking
of the soil surface, holds in moisture, encourages earthworms,
moderates soil temperatures for optimum root growth, improves
the soil as it decomposes, and prevents weeds from germinating.
A two-to-four inch layer of mulch decreases evaporation from
the soil by 70 percent or more, allowing you to water less
often (but still deeply). Keep mulch several inches away from
tree trunks and plant stems, however, for good air circulation.
Watering patterns you begin now will help or
hinder your plants' abilities to thrive
--not just survive--during the extended heat
of summer. When germinating seeds, water the beds or flats
several times a day until the plants are up, and then at least
once a day until the second set of true leaves develops. "True"
leaves look like miniature versions of mature leaves.
When seedlings are transplanted, change to
a less-frequent and deeper watering pattern to encourage roots
to grow deeply into the soil for moisture rather than spread
just below the soil surface. During hot, dry spells, these
deeper roots will have access to moisture for continued strong
growth, but the shallow roots won't. This watering pattern
will also save you time and irrigation water, since the water
will sink deeper and evaporate less. Build soil basins around
large plants and trees to prevent runoff until it's absorbed.
Avoid overhead irrigation so late in the day
that foliage cannot dry completely before sunset. Fungal and
bacterial diseases thrive in warm, moist conditions and can
develop overnight.
When transplanting seedlings or larger plants,
apply a mild solution of a balanced fertilizer such as 16-16-16,
or one that is low in nitrogen and high in phosphorous and
potassium such as 5-10-10. This gives the plant a complete
supply of the nutrients it needs for sturdy growth. A heavy
application of nitrogen such as 16-5-5 at planting time will
encourage too much green growth too soon and result in lower
yields later. Feed plants again six weeks after transplanting,
and again when the first fruit and vegetable blossoms open,
to encourage continued strong growth and plentiful fruit set.
While some manure is good for your garden,
a lot is not necessarily better, especially if it's chicken
manure and the weather is hot. Excessive levels of salt and
ammonia may result in burning seedlings and reduced yields,
if not killing the plants--and the salt remaining in the soil
may limit your choices for future crops.
Continue pulling weeds before they form flowerheads
or scatter their seeds, and you'll have fewer weed problems
later. Watering the day before weeding will ease the chore,
and weeds' entire root systems will come out more readily.
If you leave pulled weeds in garden pathways for dry mulch,
be sure to leave them with their roots up so they don't reroot.
But don't leave weeds that have already developed their seedheads--some
seeds may mature and germinate next year. You don't want your
weeds to recycle themselves!
Continue adding to your compost pile. Alternate
shovelfuls of old compost or soil with fresh grass clippings,
kitchen peelings, leaves, softwood prunings, or annual weeds
that have not gone to seed. Keep the pile evenly moist. Turning
it every week will speed the decomposition. With no turning
but good aeration, compost should be ready by the fall.
Encourage bees to visit your garden for better
pollination. They'll come more readily if you provide with
their favorite plants--including basil, borage, calendulas,
catnip, hyssop, lemon balm, mint, summer savory, thyme, and
other plants with blue flowers.
To attract butterflies to your garden, plant
asters, lantanas, buddleias ("butterfly bush"!),
marigolds, sweet williams, tithonias (Mexican sunflower),
zinnias, and other daisy-like flowers.
If you like to provide birds with nesting materials,
the Aububon Society recommends staying away from fabric, yarn,
and similar materials which hold moisture and can increase
the danger of respiratory diseases among baby birds. Instead,
provide straw, hair, and other non-absorbent materials.
Keep ants off of your hummingbird feeder by
spreading olive oil on the tip that dispenses the sweet water.
The ants will stay away, but the taste doesn't seem to bother
the birds.
Don't worry about a few aphids--they won't
harm your plants. Greater numbers can be dislodged by spraying
forceful jets of water (place your hand behind the bloom to
support it as you spray). For more severe infestations, use
insecti-cidal soaps or stronger sprays--and bring in the ladybugs!
For handy labels, use masking tape. Stick a
strip of the tape onto a container of a concentrated solution
such as liquid fertilizer. Write abbreviated instructions
on the tape with indelible ink. Rather than having to locate
and reread the full-length directions each time, just refer
to your simplified version on the tape.
Place a rubber washer around a length of dowel
at the correct planting depth to punch planting holes for
big seeds like corn and beans without bending. The washer
can be moved up or down the dowel to adjust for differences
in seed depths. Less bending means you can garden longer!
Use plastic baskets from cherry tomatoes or
strawberries to protect newly-sprouted seedlings such as corn,
cucumber, melons, and squash from birds. By the time that
the seedlings have grown tall enough to reach through the
tops of the baskets, they are no longer as tender and delectible
as the birds prefer.
Support stems of chrysanthemum plants growing
closely in beds with chicken wire unrolled the length of the
bed and staked one foot above the soil. The stems will grow
up through the holes and support themselves to their full
height without toppling over. Setting up the wire support
is easier than staking each plant, selective cutting of blossoms
is easier, and clean-up is quickly-accomplished. |