Jaune de Poitou Leek
Leeks - Allium
ampeloprasum var. porrum
Family - Amaryllidaceae
Leeks are an easily grown cool season member of the onion family
that produces quite well in Las Cruces soils and climate. Even though
they are classed as a cool season crop, they can be grown here year
round with proper timing and propagation. You can harvest this non-bulbing
allium at all stages during its growing cycle have freshly harvested
small and large leeks from the same planting.
There are many ways to grow leeks here successfully, but the planting
schedule below is the easiest and most dependable way to manage
timing and deliver a year-round supply of fresh leeks from garden
You can use the same schedule if starting seeds outdoors with some
exceptions. Your spring seedlings will mature more slowly, because
of cold nighttime temperatures, but the plants will grow quickly
once it warms up. Using row covers will speed up early growth considerably.
Starting the fall planting outdoors requires that you provide some
shade for the seedlings or they will stall out in summer heat (and
may not recover). A double layer of row cover will provide enough
shade (about 30%) to keep seedlings from stalling.
Seedling Tips -
Starting seeds in 4" pots instead of six packs provides more
root room and yields faster growth. You can grow leeks in clusters
of 2, 3 or 4 together to reduce the number of seedlings you transplant.
Below The Surface
Leeks have a shallow, dense and fibrous root system, so its important
to transplant them deeply to avoid drought and hot soils - it also
yields you longer more tender shanks for eating. Leeks grow fastest
with a constant and even supply of water. This spring I planted
leeks into an olla watered bed and into one that I have hand watered.
Leeks in the olla watered bed grew at least three times faster that
the hand watered ones. (all other conditions were as equal as possible)
Its a little extra work, but a self regulating subterranean watering
system really pays off with faster growth in leeks.
-Trim off 1/3 of the root growth and 1/3 of the top when transplanting
to stimulate root growth and reduce transplanting shock. Set transplants
up to the first leaf junction but no deeper. Set single leek transplants
on a 3-4" grid spacing - increase the spacing for clusters
of 2, 3 or 4 leeks.
Leeks grow best in rich soil with abundant organic material (how
often have you hear that?) If you are growing organic, amend the
soil with finished compost, rabbit and chicken manure two to three
months before planting - giving plenty of time for aging. If that's
not possible add finished compost, a phosphorous source such as
soft rock phosphate, bone meal, or composted bio-solids and a nitrogen
source such as cottonseed meal a couple of weeks before planting.
Leeks require equal amounts of nitrogen and phosphorous fertilization.
Our soils generally have adequate amounts of available potassium
(unless your soil test shows otherwise), but needs additional phosphorous
and nitrogen for rapid leek growth. If you are using chemical fertilizers
apply a 10-10-10 rated fertilizer before planting and side dress
when the leeks are about 1/2" in diameter.
Mulching transplants to reduce soil temperatures is really important
in spring and through summer. In winter use a very thin mulch to
increase soil temperatures.
Irrigation Tip -
- Leeks grow fastest with a constant supply of soil moisture. If
you are growing the second year for seed, during blossom set is
a critical times to avoid water stress.
Above The Surface
The only time leeks are adversely effected by air
temperatures is in the seedling stage. Once beyond about 1/4"
in diameter they take all the heat Las Cruces can deliver and seem
unfazed (if adequately watered). Fortunately leeks are seldom effected
by diseases or insect pests and can be grown in permanent beds with
little risk of culturing diseases.
Its easy to grow your own leek seed, requiring only patience and
occasional thinning. Leeks are biennials and will put up bloom stalks
in June of their second year. The flower heads take forever to bring
in mature seed, so plan on waiting until September before harvesting
seed for next year. Seeds will remain viable for 2-3 years if kept
dry and stored in a cool place. Before the seed heads are ready
to harvest you will see new leeks growing from the base. The old
plant will eventually die out leaving space for the new basal sprouts
to form into mature leeks. Sow a few of the new seeds into the old
bed and you have a permanent year round producing leek bed with
very little work.
Growing your own fresh and delicious leeks can be done easily and
dependably with basic knowledge, a fertile soil and a little attention.
Vichyssoise and Beyond
Oregon State University Commercial Production Guide
Good Gardening and Good Eating
Doña Ana Extension Master Gardener