If you are planning to grow kohlrabi in your garden this year, you might be\nwondering how big the plants and fruit will get. That way, you can plan\nthe number of plants and the amount of space you will need for your crop of kohlrabi.\n\n\n\nSo, how big do kohlrabi get? Kohlrabi\ncan grow 6 to 18 inches (15.2 to 45.7 centimeters) tall, 12 to 18 inches (30.5\nto 45.7 centimeters) wide, and produce bulbs up to 6 inches (15.2 centimeters)\nin diameter. \n\n\n\nOf course, the quality of your kohlrabi (if you get any at all!) depends on\nthe care that you give your plants. Let\u2019s take a closer look at kohlrabi,\nincluding size, growing conditions, and time to maturity.\n\n\n\nHow Big Do Kohlrabi Get?\n\n\n\nA kohlrabi plant, including the stalks, can grow up to 18\ninches (45.7 centimeters) tall, with a width of up to 18 inches (45.7\ncentimeters).\n\n\n\nThe bulb on a kohlrabi plant can grow up to 6 inches (15.2\ncentimeters) in diameter for large varieties. \nThis is a circumference of over 28 inches (71 centimeters)!\n\n\n\nKohlrabi can grow up to 6 inches (15.2 centimeters) in diameter. It should probably be harvested before it gets that large, though.\n\n\n\nHowever, keep in mind that kohlrabi bulbs will become bitter\nand tough if they get too large. You\nshould make plans to keep an eye on your kohlrabi, since they grow very\nquickly. Make sure to harvest your\nkohlrabi before they get too large and become bitter (more on this later).\n\n\n\nHow Long Does It Take Kohlrabi to Grow?\n\n\n\nKohlrabi can take between 40 and 60 days from the time you\nplant a seed to the time you get a mature plant with bulbs that are ready for\nharvest. Of course, the time to maturity\ndepends on the variety. There are both\ngreen and purple kohlrabi plants available.\n\n\n\nFor more information, check out this article on kohlrabi from the University of Illinois Extension.\n\n\n\nKohlrabi seeds usually germinate in 7 to 10 days, assuming that\nsoil temperatures are between 50 and 85 degrees Fahrenheit (10 to 30 degrees\nCelsius).\n\n\n\nFor more information, check out this article from West Coast Seeds on growing kohlrabi.\n\n\n\nDoes Kohlrabi Grow Above Ground?\n\n\n\nYes, kohlrabi grows above ground. The stem, which looks like a bulb, develops\nmostly above ground. This bulb is the\npart of a kohlrabi plant that is usually grown for eating.\n\n\n\nThere are also stalks that grow upwards from the stem of a\nkohlrabi plant. These stalks have leaves\nat the ends, and are sometimes also harvested for food when still young and\ntender.\n\n\n\nCan Kohlrabi Get Too Big?\n\n\n\nYes, kohlrabi can get too big. When a kohlrabi bulb gets too big, the stem\ngets woody and tough, and the flavor becomes bitter. The stalks and leaves will also become tough\nand bitter as the kohlrabi plant gets older and larger.\n\n\n\nTo avoid tough kohlrabi bulbs and stalks, harvest the plant\nwhen the bulb is 2 to 3 inches (5.1 to 7.6 centimeters) in diameter. Cut the bulb from the base of the plant, and\nwash off the dirt.\n\n\n\nYou can eat the bulb raw or cook it like a turnip. If you use the foliage for salad greens,\nharvest some of them when the plant is still young, before the stalks and\nleaves get tough. That way, the\nremaining stalks and leaves will help the kohlrabi bulb to continue growing.\n\n\n\nWhat Do Kohlrabi Look Like?\n\n\n\nA kohlrabi plant has a round globe (the bulb) that grows mostly\nabove the soil line. There are numerous\nshoots (stalks) with leaves at the ends that grow up from the bulb.\n\n\n\nKohlrabi grows as a bulb above ground, with stalks that have leaves at the ends. Kohlrabi can be green or purple.\n\n\n\nKohlrabi stalks and their leaves look like kale. You can eat kohlrabi stalks and leaves raw in\na salad, or you can steam or boil them like spinach. You can also use them as garnish for a dish, such\nas a stir-fry, just like you might with other microgreens.\n\n\n\nKohlrabi bulbs and stalks can be green or purple. The leaves of a kohlrabi plant are green.\n\n\n\nAre Kohlrabi Hard to Grow?\n\n\n\nKohlrabi plants like at least 6 hours of full sun per day,\nand they prefer a soil pH between 6.0 (slightly acidic) to 7.5 (slightly\nbasic).\n\n\n\nIf you are not sure about your soil pH, you should get a soil test to make sure you are in the correct range. For more information, check out my article on soil testing.\n\n\n\nKohlrabi can be difficult to grow in warmer regions, since it is a\ncool-weather crop. Also keep in mind\nthat too much heat or water stress can cause kohlrabi bulbs to become bitter,\neven if the plant does grow well.\n\n\n\nThere are many other factors that affect kohlrabi growth, including\ntemperature, watering, fertilizing, and spacing. Let\u2019s start with temperature.\n\n\n\nTemperature for Kohlrabi\n\n\n\nKohlrabi is a cool-season crop in the Brassica family (along\nwith broccoli, cauliflower, cabbage, etc.). \nKohlrabi seeds will germinate in soil temperatures as low as 45 degrees\nFahrenheit (7.2 degrees Celsius).\n\n\n\nFor a spring crop, plant kohlrabi 4 weeks before the last\nspring frost. For a fall crop, plant\nkohlrabi 6 weeks before the first fall frost.\n\n\n\nYou can find the frost dates for your area on the Old Farmer\u2019s Almanac\nwebsite.\n\n\n\nAccording to Cornell University, kohlrabi prefers temperatures in the 60\u2019s Fahrenheit (15.6 to 20.6 degrees Celsius).\n\n\n\nAccording to Bonnie plants, kohlrabi can survive frost, and a\nlight frost can even enhance flavor of the plant. However, a hard freeze will kill kohlrabi.\n\n\n\nTo protect kohlrabi from late a spring freeze or early fall\nfreeze, use cloches to cover young plants, or row covers for larger, more\nestablished plants.\n\n\n\nA cloche can be made from a plastic water bottle. It can also be used to retain warmth and\nhumidity in the soil for seeds or seedlings as they grow.\n\n\n\nWatering for Kohlrabi\n\n\n\nKohlrabi needs even watering in well-drained soil to avoid\ncracking and splitting. Water stress can\nalso lead to bitter flavor, so you may need to use mulch to keep the soil\nmoist.\n\n\n\nWater and heat stress make kohlrabi bitter, so be careful not to under water them.\n\n\n\nYou may also need to water more often if you have sandy soil, which drains\nquickly.\n\n\n\nIf you find that you have a problem with dry soil, check out my article on how to treat dry soil.\n\n\n\nOn the other hand, over watering your kohlrabi plants (or any plants for\nthat matter) can lead to root rot and eventual death. The best way to\ndecide when to water is to feel the soil with your fingers.\n\n\n\nIf the soil feels dry 2 or 3 inches below the surface, then go ahead and\nwater. Watering deeply and infrequently\nencourages stronger root systems in plants.\n\n\n\nFor more information, check out my article on over watering your plants.\n\n\n\nTry to water early in the morning, rather than at night, to allow water to\nsoak into the soil. Also, avoid getting the leaves wet to prevent rot,\nmold, and diseases.\n\n\n\nFor more information on watering, check out this article on kohlrabi from the University of Minnesota Extension.\n\n\n\nFertilizing for Kohlrabi\n\n\n\nBefore you do any fertilizing or planting, it is a good idea to add some\ncompost to your soil. This will provide\norganic material and nutrients for your kohlrabi plants. It will also improve drainage in clay soil,\nand improve water retention in sandy soil.\n\n\n\nCompost adds nutrients and organic matter to soil, and can be made from kitchen scraps and yard waste.\n\n\n\nThe best part about compost is that you can make it from recycled kitchen scraps and yard waste. For more information, check out my article on how to make compost.\n\n\n\nAfter adding compost to the soil, the University of Utah Extension suggests using 4 to 6 cups of a balanced fertilizer (such as 10-10-10) early in the kohlrabi plant\u2019s growth, to encourage bulb and leaf growth.\n\n\n\nAvoid excessive nitrogen, since this can burn plants. The same warning applies if you decide to use\nmanure to help fertilize your garden. Make\nsure that the manure is fully decomposed before using it!\n\n\n\nFor more information, check out my article on over fertilizing your plants.\n\n\n\nSpacing for Kohlrabi\n\n\n\nSow your kohlrabi seeds \u00bc to \u00bd inch (0.6 to 1.3 centimeters)\ndeep in the soil. When the seedlings\nhave 3 or 4 true leaves, thin them so that the remaining plants are 4 to 6 inches\n(10.2 to 15.2 centimeters) apart, leaving 2 to 3 plants per foot. (You can use the seedlings you pulled up as\nmicrogreens in a stir-fry or other dish!)\n\n\n\nFor more information, check out my article on thinning seedlings.\n\n\n\nLeave 12 to 18 inches (30.5 to 45.7 centimeters) between plant\nrows, to allow for easy watering, weeding, and harvesting of your kohlrabi.\n\n\n\nConclusion\n\n\n\nNow you have a much better idea of how big kohlrabi will get, in terms of both the bulb and the plant itself.\u00a0 You also know a bit more about the care that is necessary to ensure a healthy crop of kohlrabi in this year\u2019s garden.\n\n\n\nYou might also want to read my article on fall planting for cool weather crops.\n\n\n\nI hope you found this article helpful \u2013 if so, please share it with someone\nelse who can use the information. If you have any questions or advice\nabout kohlrabi, please leave a comment below.