When gardeners think about leeks, they feel that the plant is too challenging to grow. While they can be demanding, they are well worth the effort but before we get into that lets talk about the two different types of leeks. Believe it or not, there is a short seasoned leek and a long season leek. The short season cultivator is planted in the spring and harvested during the late summer and early fall. The long season cultivator can be defined as one that takes 100+ days to mature. Planting this latter cultivator depends on where you live. If you live in the north, your long season leeks will need to be planted in the spring. On the other hand, if you live in the south, your long season leeks can be planted during the late summer or fall.
To help get a jump on the growing season, you will need to start you leeks indoors. But before you reach for the soil, you will need to pull out the calendar. Leek seeds need to be planted 8 to 10 weeks before your local frost free date. Once you have that date, you can begin to prepare for the planting process. This process starts by selecting the right containers. Leek seeds will be planted ½ inch deep so the pot(s) need to be 6 inches deep with a drainage hole in the bottom. Once you have your pot(s) selected, the next step is to clean and sterilize the container. Do not skip this step. While you may have new pots or old, they do collect plant diseases and garden pests during the growing season and beyond. It is very important to start your seeds in a clean environment. To do this, one must first clean the pot(s) in water with a capful of bleach. Once they are clean, rinse them in clear water and set out to dry.
The next step consists of adding drainage material to the bottom of the container(s) and filling with a good all purpose potting soil. After the pot(s) have been filled, gently tap the container(s) on a hard surface. This will force out any air bubbles that may have built up in the soil.
Once the pot(s) have been filled and the planting date has arrived, the next step is to plant the seeds but I have a tip for doing this step. Yes, the seeds will need to be planted ½ inch deep but this can be a challenge without a measuring tool. The easiest one to use is one that you create from supplies you have at home. In this case, pull out a pencil and measure off a ½ inch from the bottom. Once you have that measurement, mark it with a permanent marker or tape.
To use your DIY depth gauge, simply poke the pencil into the soil until you reach your marked line and then plant your seed in the hole. Once that is done, gently move the soil over the hole and lightly push down. Repeat the process for all the seeds you want to plant.
Move your planted pot(s) to a location that is keep between 60 and 65 degrees Fahrenheit and water in.
Continue to monitor the soil moisture and when the leek seedlings are about 3 inches tall, you will need to thin them so that they are 1 inch apart. Do not pull the plants out that you are removing to thin. The best approach is to just cut them off at soil level.
While you are waiting for your outdoor planting date to arrive, you can begin preparing the garden space but before you get to that you need to properly select the space. Leeks require a well drained soil that is located in full sun. Once you have found that location, the next step is to prepare the garden space. First, you will need to remove any existing plant material and then turn over the soil to a depth of 12 to 15 inches. After that is done, mix in 2 to 4 inches of well seasoned compost.
As your planting date approaches, you will need to harden off your leeks. The hardening off process is simple and just means that you slowly introduce the outside to your leeks. This will need to be done over a time span that ranges between a week and two weeks. Once the leeks have been hardened off, the next step is to get them in the garden. At this stage, you have two techniques by which to get the leeks in the ground. The first technique consists of digging a trench that is 6 inches deep. Next, place the leeks in this trench so that they are 6 inches apart. Once you have all the leeks planted, fill in the trench so that the leeks are covered. As the leeks grow, add more soil to blanch the stalks.
The second technique consists of planting the leeks in wide rows. When using this approach, you will need to space the leeks out so that they are 8 to 10 inches apart and 6 inches deep. To make the planting depth easier, take the handle of a rake or hoe and mark as described for the pencil technique. After that is done, all you have to do is poke the handle into the ground and then drop the leek seedling in the hole and cover up. To get the most out of the blanching, place soil in a hill fashion on top of the leeks.
Regardless of which technique you choose, do not forget to water in the seedlings.
Continue to monitor soil moisture and water as needed. As far as fertilizing goes, leeks love nitrogen. In doing so, you will need to select a fertilizer formulation that has the first number higher than the other two. Apply this fertilizer once a month to the leeks.
While leeks normally do not have many problems, there are a few that are simple to address. The first problem comes from weeds. Leeks do not compete well with weeds. To keep the competition down, make sure to remove any weeds as soon as they appear. The second problem that leeks face is from two pests, which includes onion maggots, and onion thrips. Both of these pests can be treated through organic gardening techniques. One of the easiest ways of controlling these pests starts when you first place the leeks in the ground. To keep the insects way from the leeks, simply top the leeks with a floating row cover. To keep the insects from entering the floating row cover from the edges, place soil along the edges.