Plants that are already rooted in pots and are not divided are the easiest to handle without setback. If shipping, they should be shipped either dormant or when the leaves have fully expanded and hardened off. Care should be taken to avoid damaging leaves. Whether they are to be kept in pots or planted out, remember to keep exposure to direct sunlight to a minimum for the first year. Planting from a pot to the ground is best done before leafing out, just after the leaves have hardened off, or at the end of the season. Plants that are cut face difficulties that uncut plants do not face. Cuts through thick rhizome are vulnerable to rot, and should be treated with a fungicide. Mild, safe fungicides work quite well so there is no need for dangerous products. Dividing hostas should be done after the leaves have fully hardened off in late Spring if maximum growth is the goal. At this time, the new roots are beginning to form. The act of dividing a hosta can greatly reduce its ability to supply water to the leaves because the root system has suffered traumatic injury. To reduce setback to a minimum when it is leafed out, the divided plant needs some special treatment. Dividing a plant with a new set of leaves but before the new set of roots has formed works best because the amount of leaf material will determine the amount of roots that will form if conditions are good. For this to happen, it is imperative to protect those leaves so the plant will produce the most roots. If dividing in Spring after the leaves have formed, a division with lots of leaf material and few roots will make a better plant than one with lots of roots but few leaves, but only if the leaves are protected enough to last the season. If dividing late in the season or in very early Spring before they have leafed out the reverse is true, and the roots are what is important. Late Spring division will give the best increase in size, but it must be done so as to avoid losing leaf material to get the best results. Keep in mind that damage to the root system makes it impossible for the plant to get the same amount of water to the leaves. Because of this, both the mother plant and the removed division will lose leaves if not handled with care. Losing leaves will result in less root formation as there is less demand for it with fewer leaves to supply water to. Less root formation in turn will lead to a smaller plant the following year. The key to getting the best results is to reduce the amount of water the leaves need so they remain healthy and new roots are produced to supply them. Evaporation of water from leaves is the main way a hosta loses water. During hot summer days when direct sunlight is hitting the leaves, demand for water from the roots to replace that evaporated away can exceed even an undamaged plant's ability. We see this as wilting, scorching, and burning. As the day cools off and the sun no longer hits those plants, they begin to "perk up" as the demand for water lessens and the roots supply enough for them to return to their normal appearance. An undamaged plant can take quite a bit of this kind of stress without losing leaves. A divided plant will suffer far more, and can even be killed if the stress is great enough. To get the best growth from Spring division, divide when the leaves are fully expanded and hardened off for 2-3 weeks. Once the plant is cut, both the removed division and the mother plant should be grown in a minimum of direct sunlight. Good indirect light is best, and no more than a little direct early morning or late evening sun should touch the leaves for the rest of the growing season. If the leaves are protected from damage of any kind, a hosta will try to produce enough roots to keep them supplied with water. This will produce maximum new root growth with no leaf loss from water stress. No leaf or root cutting/pruning should be done, and plants should not be allowed to dry out completely. If plants are handled this way, there should be little setback to the mother plant if it had four or more divisions prior to cutting. If there were less, some setback is unavoidable, but will be the minimum that could be expected. The removed division should come up the next year with an increase in size, either as a bigger division or as more than one. Another factor to take into consideration when receiving a hosta from someone else is the type of roots a hosta has formed. Hosta roots adapt to the situation they find themselves in when they are being formed just as the leaves do. If in a very light pot mix, they will be fine and numerous. If in a heavy clay soil, they will be thick and few. Cutting before the new roots develop gives the plant a chance to adapt its new roots to its new location. Well adapted roots can supply water to the leaves better than poorly adapted roots can. Taking a hosta that has roots adapted to a very light mix and planting it in garden soil will reduce its ability to supply water to its leaves, so even if it was not cut direct sunlight should be avoided for the first season. Potted hostas can have a difficult time adapting to their new home, so should receive basic care. If you want to transplant them to the garden, the best time to do so is right after they have fully leafed out and those leaves are firmed up and hardened. Remember that the old roots are not adapted to your soil, so the plant will not be able to get water to the leaves as well as it did in the pot. Follow the same sunlight rules as with divisions for best results. A good alternative is to keep the pot in a fairly shady place until Fall and plant then. This will not work quite as well but is effective in keeping the plant from losing ground from transplant stress. Hostas are tough plants, and will usually survive no matter how they are handled, often without much setback. There are times though when treating them roughly does impact their growth badly. For this reason, it is worth thinking about handling them with care if they were expensive auction purchases. The above instructions will reduce stress to a minimum and give the plant its best chance for maximum growth after the traumatic business of cutting, shipping, and transplanting.
Ten Steps to Good Results with Auction Plants:1. Cut your hosta after the leaves have fully formed and hardened off for 2-3 weeks. 2. Keep both the mother plant and the removed division out of direct sunlight for the rest of the season. 3. Do not let cut plants dry out completely the first season. Wilting means stress from water loss and is sign of danger. 4. Do as little damage to the leaves and root system as possible when dividing and handling. 5. The division will form roots to match the leaves before the season ends, so protect the leaves at all costs. 6. Avoid planting in too different a soil for the first summer. "Pot roots" work best in pots; "Ground roots" best in the ground. 7. Use a mild fungicide on cuts through rhizomes. 8. Always keep newly acquired hostas in LESS sunlight than they were in where they came from for the rest of the season. 9. Use a fertilizer that is higher in root-promoting "P" and "K", rather than one high in "N". 10. Plant away from other plants for a year to be sure it is healthy and free of disease.
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