VEGETABLES
Bolting and Buttoning in Cole Crop Plants
Broccoli, cabbage and cauliflower are cole crops that have a
tendency to bolt (go to seed) or button (produce an extremely small
head) if plants are not grown properly. These crops need to be kept
actively growing through their production cycle, including growing
transplants from seed. If they slow down due to under-fertilization or
are stunted due to overgrowing their container, buttoning or bolting is
more likely. Therefore, be sure to properly fertilize plants grown from
seed and ensure they have enough light. The easiest way to fertilize
transplants is to use a potting soil with fertilizer already added.
Light may be more of a challenge. Often natural sunlight is not
sufficient unless the plants are in a greenhouse. Therefore, additional
light is often needed. Click here for a video on how to build a grow light.
If you are not growing your own transplants but rather selecting
plants later in the month for transplanting, choose small, stocky, dark
green plants. Even after transplanting, these plants need to be
well-fertilized. Fertilize at transplanting with a starter solution and
continue to fertilize every 2 to 3 weeks until harvest. Both buttoning
and bolting are irreversible. Once a seed stalk starts for form, nothing
can be done to force the plant to produce a normal crop. (Ward Upham)
Rhubarb
Rhubarb is a perennial vegetable that can be a bit tricky to grow
in Kansas. It is native to northern Asia (possibly Siberia) and so is
adapted to cold winters and dry summers. However, it is susceptible to
crown rot and should not be subjected to “wet feet” and therefore should be
grown in a well-drained soil. The addition of organic matter can
increase drainage as well as
raise the soil level so that crown rot is less likely. Also, have a
soil test done as rhubarb does best with a pH below 7.0.
Rhubarb should be planted from mid-March to early April in Kansas.
Mix 5 to 10 pounds of well-rotted barnyard manure into the soil for each
10 square feet of bed before planting.
Rhubarb is propagated from crowns (root sections) that contain one
or two buds. Plants should be spaced 2 to 3 feet apart in the row with 4
to 5 feet between rows. The crowns are planted shallow so that the buds
are just one-half to 1 inch below the soil surface. Firm soil around the
crowns and make sure they are not in a depression that holds water.
Recommended varieties include Canada Red, Crimson Red, McDonald and
Valentine.
Rhubarb needs rejuvenated at least every 5 to 10 years and should
be dug and divided from mid-March to early April. Use a cleaver or axe
to cut crowns into sections that each contain one or two buds. Plant as
described above.
Newly transplanted rhubarb should not be harvested the first year
so the plant can recover from the transplant process. Only a few stalks
should be harvested the second year to allow the plant to continue to
build up its energy reserves. The harvest season for plants that are
three years or older usually lasts about 8 weeks. Harvest only the
largest and best stalks by pulling them
slightly to the side so that they break away from the plant. Never
harvest over one-third of the
leaf stalks at one time. Only the leaf stalk (petiole) is eaten as the
leaf blade contains oxalic acid
and is poisonous.
Established rhubarb should be fertilized in late March. Fertilize
according to soil test or use a 10-10-10, 12-12-12 or similar fertilizer
and broadcast or band at the rate of 1.5 to 2 pounds per 100 square feet
or about 1/2 cup per plant.
An additional 1/4 cup of fertilizer per plant of a high nitrogen
fertilizer such as a 27-3-3, 28-4-4 or something similar in late June or
July after the last harvest is often helpful to stimulate recovery from
the harvest season. Though most of these high nitrogen fertilizers are
lawn fertilizers, each will work well for our purposes as long as they
do not contain weed killers or weed preventers.
Mulches can be used to reduce moisture loss, prevent weed growth
and provide winter
protection. However, it should be pulled away in the spring to allow the
soil to warm so that
early growth is encouraged. (Ward Upham)
Time to Plant Potatoes Approaching
St. Patrick’s Day is just around the corner, so it is time to think
about getting seed potatoes in the ground. Actually any time from mid-
to late-March is fine for potato planting. We may have to plant later
this year if soil remains wet.
Be sure to buy seed potatoes rather than using those bought for
cooking. Seed potatoes are certified disease free and have plenty of
starch to sprout as quickly as soil temperatures allow. Most seed
potatoes can be cut into four pieces, though large potatoes may yield
more, and small less. Each seed piece should be between 1.5 and 2
ounces. Seed pieces this size will have more than one eye.
Each pound of potatoes should yield 8 to10 seed pieces. Cut the
seed 2 to 3 days before planting so freshly cut surfaces have a chance
to suberize, or toughen, and form a protective coating. Storing seed in
a warm location during suberization will speed the process. Plant each
seed piece about 1 to 2 inches deep and 8 to 12 inches apart in rows.
Though it is important to plant potatoes in March, emergence is slow. It
is often mid- to late-April before new plants poke their way through the
soil. As the potatoes grow, pull soil up to the base of the plants. New
potatoes are borne above the planted seed piece, and it is important to
keep sunlight from hitting the new potatoes. Exposed potatoes will turn
green and produce a poisonous substance called solanine. Keeping the
potatoes covered will prevent this.
If you are planning on planting potatoes for a fall crop, save back
some of the seed potatoes for planting in mid-July as it is hard to find
seed potatoes during the summer. Store the potatoes in a cool location
or in a refrigerator. It is especially important to let the potatoes
sit in a protected location for 3 to 4 days after cutting as they tend
to rot unless they have a chance to form a protective layer over the cut
surface. We will have a reminder of when to plant in a July newsletter.
(Ward Upham)
Use Wide Rows for Certain Vegetables
Lettuce, radishes and spinach are planted early enough that weeds
are usually not a problem. Though these plants can usually be planted
starting in mid-March, planting may need to be delayed due to cold, wet
soils this year. Usually we can plant as late as mid-April for these
plants. If space is at a premium, gardeners can plant a wide row and
get more production out of a small space. How wide? Usually 12 to 18
inches is about right. Leaving aisles between wide rows allows for
convenient harvesting.
Seed can be planted in several rows close together to make a wide
row but it is easier to scatter seeds uniformly over the area. After
seeding, tamp down the row lightly with the back of a hoe to eliminate
air pockets. Then pull soil from the sides of the row with the back of
a garden rake to cover the seed. One-quarter inch of soil over the seed
should be good.
Be careful to not sow too densely as too much competition can stunt
plants. Space seed according to the instructions on the seed packet.
If you do happen to sow too thickly, plants can be thinned later.
It is best to go back to a single row for later planted crops to
allow for easier weed control. (Ward Upham)
ORNAMENTALS
Cut Back Ornamental Grasses
March is a good time to remove dead foliage from ornamental
grasses. Grasses green up earlier if foliage is removed and are more
attractive without a mixture of dead and live leaves. A number of tools
can be used including hand clippers, weed whips (if the foliage is of a
small enough diameter), weed whips with a circular blade, or even a
chain saw. Use the top of the chainsaw bar to cut so the saw doesn’t
pull in debris and clog.
Also, it is often helpful to tie foliage together before cutting so
it doesn’t interfere and is easier to dispose of. Burning is another
option — but only if it is safe and legal to do so. Note that these
grasses may not burn long, but they burn extremely hot. Even so, the
crown of the plant is not damaged and new growth appears relatively quickly.
If the center of the clump shows little growth, the plant would
benefit from division. Dig up the entire clump and separate. Then
replant the vigorous growth found on the outer edge of the clump. (Ward
Upham)
FLOWERS
Iris Leaf Spot Control Starts Now
Now is a good time to begin control measures for iris leaf spot by
removing old, dead leaves. Iris leaf spot is a fungus disease that
attacks the leaves and occasionally the flower stalks and buds of iris.
Infection is favored by wet periods during the spring, and emerging
leaves eventually show small (1/8- to 1/4-inch diameter) spots. The
borders of these spots are reddish, and surrounding tissue first appears
water-soaked, and then yellows. Spots enlarge after flowering and may
coalesce. The disease tends to be worse in wet weather and may kill
individual leaves.
Though the disease will not kill the plant directly, repeated
attacks can reduce plant vigor so that the iris may die from other
stresses. Spores are passed to nearby plants by wind or splashing water.
Because this disease overwinters in old leaves, removal and
destruction of dead leaves will help with control. For plants that had
little infection the previous year, this may be all that is needed.
Plants that were heavily infected last year should be sprayed with
chlorothalonil (Bravado Fungicide, Fertilome Broad Spectrum Landscape &
Garden Fungicide, Ortho Garden Disease Control, GardenTech Daconil,
Bonide Fungonil, Bravo Flowable Fungicide) or myclobutanil (Immunox,
F-Stop Lawn & Garden Fungicide, Fungi-Max) starting when leaves appear
in the spring. Repeat sprays every seven to 10 days for four to six
sprays. Iris leaves are waxy, so be sure to include a spreader-sticker
in your spray to ensure good coverage. (Ward Upham)
MISCELLANEOUS
Don’t Work Wet Soil
Resist the temptation to work any soil if it is wet. Doing so
destroys the structure of the soil resulting in clods that may not break
down all summer. To determine if a soil is too wet to work, grab a
handful and squeeze. If water comes out, it is much too wet. Even if no
water drips out, it still may not be dry enough to work. Push a finger
into the soil you squeezed. If it crumbles, it is dry enough, but if
your finger just leaves an indentation, more time is needed. Be sure to
take your handfuls of soil from the depth you plan to work the soil
because deeper soils may contain more moisture than the surface.
If there is a small area that you wish to plant in a few weeks and
it much too wet to work, try tarping the area during wet weather and
uncovering when it is dry. This will allow the soil to dry enough to
work by the time you are ready to plant. (Ward Upham)
