In some parts of the world, particularly Europe, potatoes are considered to be a cleaning crop. This is something to take into account, particularly when it comes to crop rotation, and in gardens where weeds are a problem.

Of course whatever veggies you are planning to grow, it is vital to prepare the ground well before you plant. If you take the trouble to check the soil and adjust it according to the required pH and nourishment needed for the different crops you are planning, you will sure to be rewarded with good yields.

The Importance of "Clean" Ground

If the ground hasn't been used for growing before, it may need to be cleared first. If there are trees and shrubs that need to be removed, you may need to dig deep into the ground to get rid of roots. If it is a new property that has just been built on, there may be rubble that needs to be removed.

Apart from these factors, when horticulturists talk about clean and 'dirty' ground, they are usually referring to the presence of weeds that make the ground totally unsuitable for the growth of certain plants. These include oxalis, water grass and couch grass, all of which are perennial nuisance plants. There are others too, all of which quickly establish themselves and thrive on the moisture provided to the newly sown plants.

Generally it is the crops that may be directly sown into the ground that come off second best; these include beans and peas, beets, carrots and parsnips. Vegetables that are more commonly transplanted out when the seedlings are already quite established – like cabbages, cauliflowers and tomatoes – fare better because the  beds can be reasonably easily weeded and cleaned without disturbing them.

What Makes Potatoes a "Cleaning" Crop

The reason that potatoes are considered to be a cleaning crop is because when they thrive in good conditions, they produce a nice, dense canopy of foliage that both shades the soil and generally suppresses the growth of weeds.

If you have grown potatoes you will know that it is common practice to "draw" the soil up as the plants grow, so that a substantial ridge of earth is created once the leaves are fully formed. This "earthing up" procedure also has the effect of smothering weeds, particularly annuals.

Even so, you cannot rely on potatoes to get rid of weeds on their own. Every veggie gardener needs to follow a vigilant "cleaning" process of their own, and to remove weeds before they establish themselves and damage their crops.