Harvesting homegrown vegetables can be just as important as growing them as some crops can quickly go past their best and loose precious flavour and texture. Harvesting at just the right time is important to get the best taste from some crops while knowing when and how to pick others will encourage the plant to produce more crop. We have compiled a list of vegetable harvesting guidelines for the most common vegetable crops with advice on picking and storing so without further ado here we go: Harvesting Artichoke, Jerusalem. Jerusalem artichokes will produce masses of tall foliage over the Summer but aren't harvested until October. Roots can be left in the ground over winter once the foliage has died back. Remember Jerusalem artichokes are very persistent so if you wish to grow something else in the same space next year you will need to remove every single little tuber (this is virtually impossible!) or they will re-grow next year. Harvesting Asparagus Asparagus should only be harvested in the third year after planting, cut the spears at ground level taking care not to damage new emerging spears. If new spears start to get thinner stop harvesting and leave till the following year. The maximum harvesting period for Asparagus plants is 6 to 8 weeks after which you must let the spears grow on to produce ferns which will process and transfer energy to the roots for the following season. Harvesting Bean, Broad Pick broad beans weekly when the pods are fully developed but the seeds inside still tender. Immature finger thick (about 8cm long) beans can be eaten whole (pod included) or wait to mature for larger beans. Don't let the beans so large that they are bursting from the pods or they will be hard and bitter. Pick from the bottom up as lower beans will mature first. Harvesting Bean, Runner & French You should be able to harvest your beans 3 weeks after the first flowers have appeared. Younger beans are more tender while older beans are more bitter and stringy so best picked before they reach full size. Don't let the beans mature on the vine or the plant will deem its work done (it has produced mature seeds) and will stop producing more beans. Once the plant has ceased production it can't be re started by picking so harvest at least once a week. Harvesting Beetroot Best harvested when roots are 10 - 15cm in diameter unless you grew them at close spacings where you can harvest every second beet at 6 - 8cm. Twist off the leaves rather than cutting to avoid the roots bleeding. Beetroot harvested for storage should be pulled in October and stored in boxes of moist sand. In well drained soil or raised beds beets can be left in the ground to overwinter. Cover with a layer of straw for extra protection in very cold winters. Harvesting Brussels Sprouts Sprouts should be harvested before the buds open while they are still tight and hard and about 1 inch in diameter. Once the sprouts start to open they are termed as 'blown' sprouts and are not good for cooking. Start to pick from the base of the stem as they will mature first, twist each sprout to break away from the plant. Sprouts have a long harvesting season of about 2 - 3 months. Remove stems once cropping has finished as they can be used for overwintering protection by aphids. Harvesting Calabrese Harvest when the central flower head is large enough and contains clusters of tight green buds. Check the plants at least twice a week as the buds will quickly begin to open and produce flowers meaning the crop is past its best. Early sown calabrese is ready towards the end of June, later crops in the Autumn. Cut the central stem about 15cm below the flower head with a sharp knife taking care not to damage the leaves. 2 or 3 weeks later new heads will appear further down the stem similar to the main head but smaller. Harvesting of secondary shoots can continue for up to 2 months providing the soil around the plant is kept moist, any drought will reduce yields. Harvesting Cabbage Harvest when cabbage heads are firm but before they split open. Conical Spring cabbages don't form a hard round head but should feel firm through the centre of the pointed head. Dutch cabbages are harvested in late October and can be stored in a cool frost free shed. Remove the central head by cutting the stem with a sharp knife leaving the large outer leaves attached to the stalk. Cabbage 'sprouts' will grow around the cut stem for later extra harvest. Harvesting Carrot Carrots are best dug when the roots are about 3-4 cm across the top, larger roots will not be as sweet and will tend to become woody. Dig around the roots with a garden fork and gently pull the roots up. Twist off the leaves and use immediately or store in boxes of moist sand. In well drained sandy soil or raised beds carrots may be left in the ground over winter which can improve the flavour as starch is converted to sugar. Cover with a layer of straw mulch to protect from hard frosts. Overwintering outside is not recommended in areas where slugs, mice or rats are a problem. Harvesting Cauliflower Harvest when the curds (heads) are white, firm and compact. if left to mature the heads will quickly open and begin to flower. Maturing curds can be protected from the sun by folding leaves over the centre of the plant though this usually isn't necessary with modern varieties . As with broccoli and calabrese keep an eye on plants when approaching maturity so make sure you catch them at their best. If too many cauliflower mature at the same time they can be cut and hung upside down in a cool shed and will keep for 2-3 weeks. Harvesting Celery Celery is ready to pick when plants are approx 30cm tall and should be harvested within 3-4 weeks or it will become stringy. Always make sure celery is well watered especially towards harvest time and when mature celery is standing waiting to be picked. Celery can be cut at the base of the plant to avoid damaging neighbouring plant roots by digging. Roots can be dug out later when the bed is being cleared. Harvesting Courgette Harvest courgettes when the fruits are about 10cm long, this is when they are at their best. If left to mature they will grow much larger and while still useful for cooking don't have the flavour of the less mature fruits. Regular picking when small will also ensure a long cropping period with overall yield being better than if you harvested larger fruits. If large fruits are allowed to develop on the plant productivity will decrease dramatically. Harvesting Garlic When the leaves start to yellow and die back stop watering the plants (clearly there's not a lot you can do in wet weather), this will help cure the garlic below ground. When most of the leaves have turned brown or yellow but before the stem falls over the garlic is ready to harvest. Don't pull garlic but dig carefully around the bulb with a fork to dislodge the roots. Dry the bulbs outside in warm, dry weather or indoors in a tunnel or greenhouse if conditions are wet. Store in a cool, dry place. Harvesting Kale Kale is ready when the leaves are about the size of your hand. Always pick the lower leaves avoiding the central growing tip as the plant will stop this is removed. Remove any lower yellow leaves and discard as they can encourage pests and diseases. Kale is very hardy and will last through the winter and well into Spring if picked correctly. The plant will resemble a miniature palm tree by spring but will provided many tasty and highly nutritious meals along the way. Stop picking when flower heads form or the stems become coarse and woody. Harvesting Kohl Rabi Kohl Rabi is in danger of getting woody if left to get too large with the optimum size being about the size of a tennis ball. To lift either pull entire plant or cut below the base of the swollen stem leaving the root in the ground. Use straight away or trim the outer leaves (but not the central tuft) and store in boxes of moist sand in a cool, dry place. May stand over winter in mild areas but quality will deteriorate if not protected by a straw mulch, fleece or cloche. Harvesting Leeks You can begin harvesting leeks when they are quite small, about the width of a broom handle. This will ensure a long harvesting period with larger leeks being used later on. Gently lift by loosening the soil around the roots with a fork. Leeks will remain in the ground over winter and should be lifted when required as they don't store well. If the space is required for a new crop in Spring before the leeks are harvested they can be dug and placed in a shallow angled trench and covered with soil to keep them fresh. Harvesting Lettuce Lettuce should be picked soon after the hearts form as they will run to seed quite quickly once ready. Sow small amounts regularly to avoid gluts of lettuce which all mature at the same time. 'Cut and come' again lettuce is harvested by picking the outer leaves and allowing the centre of the plant to grow on while full heads of lettuce are picked by removing the entire plant. Lettuce turns bitter when it runs to seed so unpalatable raw but can be cooked and used in soup to avoid wasting the plant. Harvesting Onion Harvest Onions when the tops are more yellow than green and have fallen over. Loosen the roots with a fork so start the curing process and pull the onions 2 weeks later. Dry onions outside in the sun if conditions are favourable or in a greenhouse or tunnel if the weather is wet. When dry onions can be tied in bunches and stored in a cool, dry place. Handle carefully as rot problems in storage start with tiny cuts and bruises made when handling onions. Winter storage life can be extended by cutting off any roots which develop in late winter. Harvesting Parsnip Parsnip roots can be harvested from mid October but will keep in the ground over winter provided beds are well drained and not prone to waterlogging. Parsnips will actually taste better after a frost because the cold causes them to convert starch in the roots into sugars. A mulch of straw will help prevent the ground freezing making them easier to dig in cold weather. If parsnips need to be lifted due to damp ground they can be stored in boxes of damp sand in a cool shed but flavour will be better if left in the ground. Harvesting Pea Peas should be harvested when peas are fully developed and nearly fill the pod. Seeds (peas) should not be allowed to develop fully as the plant will stop producing new flowers and yields will be greatly reduced. A secateurs or sharp scissors is a quick and easy way to harvest pea pods without damaging the plant. You can also harvest by hand by holding the top of the pod while you pull and leaving the remains of the original flower on the vine. Mangetout and Sugar snap peas are harvested according to taste with sugar snap varieties being juicier if allowed to bulk up and produce peas inside the pod. Harvesting Potato New potatoes are dug as you need them as they don't store well so are better left in the ground, they should be ready from July onwards. Once the potato has flowered the foliage will start to turn yellow/brown and die back which means the potatoes are ready to dig. N.B. Some potato varieties won't flower depending on the weather for that year, dig a plant to test in early July. If blight is noticed on the leaves remove the effected parts of the plant and destroy. If the problem persists remove all the foliage right down to ground level. If the issue is caught in time the spores will be prevented from reaching the tubers below and the potatoes underground should be fine. Maincrop potatoes are harvested in October for storage over the winter. Store in boxes of damp sand in a cool place. Use any damaged potatoes straight away, only store healthy tubers as disease can quickly spread and ruin your harvest. Harvesting Pumpkin As harvest time approaches cut away any shading leaves to help the fruits mature. Harvest pumpkins before the first frost leaving time for the skins to harden, you will notice cracks on the skin and stem when properly cured. Leave the stalk at the top of the fruit on as this reduces the chance of rot and can be used as a handle. Store in cool frost free shed for up to 3 months. Harvesting Radish Summer radish is quick growing and should be harvested 4-5 weeks after sowing or they will get woody and go to seed. Winter radishes taste best when left in the ground but should be covered with fleece or straw mulch to protect from frost. In wet areas radishes should be harvested in October and stored over winter in boxes of damp sand. If left in the ground Winter radishes will produce very tasty edible seed pods (known is India as moongre) which are delicious in salads or stir fries. It's worth leaving one or two in ground to try these spicy seed pods. Harvesting Swede Harvest swede from early Autumn right through till Spring depending on when you sowed them. Loosen the roots with a fork and lift by grasping the foliage and pulling. Swede can be left in the ground over winter but if you live in a wet part of the country it may be safer to lift the crop and store in boxes of moist sand. Harvesting Turnip Turnips are best harvested small when the roots are 5 - 10cm in diameter, any larger and they are prone to becoming woody. Summer turnips can be harvested as required, Autumn maturing varieties can be harvested and stored in boxes of moist sand for up to 3 months.