Growing potatoes in the home garden is a great way to provide your family with healthy and nutritious potatoes all year, but it does come with its challenges. Potatoes should not be planted in the same spot yearly and must be rotated with other crops. Find out how to rotate your potatoes and what to do if you are limited on space and can’t rotate them as recommended.
What is a crop rotation?
Crop rotation is the practice of growing vegetables in the same plant family in a different location each year. Understanding what plant family your desired veggies belong to is vital to successful crop rotation.
What are the common plant families for garden veggies?
Common garden vegetables fall into several plant families. Check the chart below to determine what plant family your veggies belong to before making plans for rotating your crops. If the vegetable you plan to grow is not in the chart, ask the nursery attendant which plant family it belongs to or read the descriptions in seed catalogues.
| PLANT FAMILY | Common Garden Vegetables |
| Onion Family | Garlic, chive, leek, onion |
| Parsley Family | Celery, parsley, carrot, dill, cilantro, parsnip, fennel |
| Cabbage Family (cole crops) | Cabbage, broccoli, collard, kale, cauliflower, Brussels sprouts, turnip, mustard greens, arugula, kohlrabi |
| Cucurbit Family | Cucumber, watermelon, cantaloupe, squash, honeydew, pumpkins |
| Bean Family (legumes) | Bean, pea, peanut, soybean |
| Nightshade Family | Potato, tomato, pepper, eggplant, tomatillo |
| Sunflower Family | Endive, lettuce, artichoke, sunflower, escarole |
| Amaranth Family | Beet, Swiss chard, spinach |
Why is crop rotation important?
Veggies in the same plant family have the same nutritional needs, attract similar pests, and suffer from many of the same diseases. All three are important reasons to practice crop rotation. Here’s why:
Nutrient Depletion: Plants in the same family, such as tomatoes, peppers, and potatoes, typically have similar nutrient needs. That means they may deplete the soil of specific nutrients if grown in the same location year after year.
Planting veggies from another plant family, such as cucumbers, melons, and squash, in the area where your tomatoes or peppers were grown the previous year allows the nutrients to replenish.
Pests: Vegetables in the same plant family often attract the same insect pests. For example, the Colorado potato beetle will attack other members of the nightshade family, such as tomatoes. Colorado potato beetles overwinter in the soil and emerge in the spring. If you plant vegetables in the nightshade family in the same location, they will provide good host plants for the Colorado potato beetle. Moving them to a new location helps prevent a Colorado potato beetle infestation.
Disease: Disease-causing organisms often live in the soil and affect members of the same plant family. For example, damping off, root rot, vascular wilts, and nematodes all live in the soil. If these diseases infect your veggies, they will continue to live in the soil.
Rotating your vegetable crops lessens the chances of your vegetables contracting the same diseases the following year. According to the WA Government Department of Agriculture and Food, you should wait two to five years before replanting the same vegetable family in the same location if soil-borne diseases have infected it.
Can I grow potatoes in the same plot every year?
It may be tempting to grow your potatoes in the same location every year, especially if they have performed well for you, but it really isn’t a good practice. Growing your potatoes in the same plot every year runs the risk of depleting the soil of the vital nutrients your potatoes need, increasing problems with pests (such as the Colorado potato beetle), and may make your potatoes more susceptible to diseases such as blight.
How often should I plant potatoes in the same plot?
Vegetables in the same plant family should not be planted in the same garden plot every year. They should be rotated on a three-year cycle. That means growing your potatoes in another section of the garden for at least two years before planting them in the original area again.
An example of a good crop rotation?
Good crop rotation means developing a plan and rotating your vegetables according to their plant family on a three to a four-year cycle. This allows the soil to replenish vital nutrients and helps control pests and diseases. Here’s what you need to do.
YEAR ONE
- Determine the plant family your vegetables belong to by consulting the previous table or looking up any vegetables that are not on the list.
- Make a list of vegetables and plant families for your reference.
- Note the number of plant families you will be growing in your garden.
- Sketch your garden area.
- Divide the garden into sections designated for each plant family on your list. For example, if you are growing vegetables from four plant families, you can divide the garden into four sections. However, if you are growing vegetables from six plant families, you must divide your garden into six sections. Keep in mind that sections do not need to be divided equally. Consider the number of veggies in each section and the room they require to grow.
- Number the sections and assign each plant family a section. Note the specific vegetables at this time.
YEAR TWO
- Refer to your sketch and move each plant family to a new section. Many find it easiest to move everything to the right one space.
- Adjust the size of the sections as necessary but avoid expanding an area and accidentally planting members of the same plant family in the old location.
YEAR THREE
Repeat the process from year two.
YEAR FOUR
You can now safely plant your potatoes in their original location.
What do you do if you don’t have enough room to rotate your crops?
If you have a small gardening area, rotating the location of your potatoes to a new place on a three to four-year cycle may be a challenge. Fortunately, Horticulture Online offers valuable tips for combating nutrient depletion, pests, and diseases when you cannot rotate your crops as well as you should.
1. Disease: Late Blight is one of the most common diseases that affect potatoes, but it doesn’t live in the soil. Late blight is airborne and can travel for miles. Rotating your potatoes a few feet in the garden isn’t likely to prevent issues with blight. Here are some tips for avoiding blight.
- Mulch your potatoes and water them at the soil level, avoiding watering the foliage.
- Grow blight-resistant varieties.
- Keep the garden free of weeds and debris.
2. Insect Pests: The most common insect pest on potatoes is the Colorado potato beetle which overwinters in the soil. It is vital to keep them under control, even after the potatoes have matured.
- Handpick or use natural or chemical pesticides to eradicate Colorado potato beetles until frost.
- Discard potato foliage and plant parts away from the garden.
- Mulch your potatoes with straw or hay to prevent larvae from entering the soil to pupate.
3. Nutrient Depletion: Potatoes remove nitrogen, phosphorus, and potassium from the soil, but that shouldn’t be an issue as you can fertilise and amend the soil with organic matter to return the nutrients to the soil.
- Test the soil to determine the type and amount of nutrients your soil needs. Your local University Extension likely offers soil testing for a minimal fee. The test results will include a detailed analysis of your soil and outline steps you should take to replenish any nutrient deficiencies. Alternatively, you can do a soil test at home yourself with a kit bought online.
Summary
It is always best to rotate the location of your potatoes to prevent issues with disease, insect pests, and nutrient depletion in the soil. However, if you have a small area for growing, rotating your potatoes with other crops can be challenging. Plant your potatoes in a new location on a three-year rotation if space allows. Otherwise, follow good practices to avoid issues with growing them in the same spot for more than one year.
