Amur Maple seedlings! Bonsai noobie

[Leo in N E Illinois]

Your seedlings just sprouted in middle of September. They will need at least 60 to 90 days of growth to develop and store the energy they would need to survive a winter dormancy. The closer to 90 days or more you can get the better. (zone 3 hardy plants can get by with a very short growing season) When does your average first frost come? If your first frost comes before December 15, you will need to protect these seedlings from all frost, and bring them inside for the winter, and keep them growing in your light garden. Your photo showed that you have the lamps hanging just above the leaves, this is good, they will need the brightest light you can give them once they come indoors. Put them out again in spring, and then never keep them indoors again. Amur maple is not well adapted to indoor growing.

Read the information in the articles archive on the Evergreen Gardenworks website that @gdy200 posted. Brent Walston's articles are one of the best collections of articles on how to bring seedlings and nursery stock up to the point of being ready to become bonsai. The first 5 years your seedlings really won't be "bonsai", they will be seedlings in training to become bonsai - "pre-bonsai". At this stage what you know about raising tomatoes, cucumbers and houseplants will really apply. Kepp them growing fast and healthy. You want sturdy growth. You want full sun growth so that internodes will be short and branches will be thicker. Soft lush growth is not what you are looking for. Read the info on Brent's website.

Your update picture the leaves look yellowish. This may be because the photo is overexposed, but if the leaves are yellowish in real life, it is time for fertilizer. Not too heavy, maybe half strength of the dose you would give tomatoes. You do want enough to get the leaves a rich light green. I saw that you repotted, this is good, those tiny peat plugs are hard to keep moist once the tree begins rapid growth.

Keep them outside until just before your first frost. Then put them back in your light garden, but do not put them on the heat mat. Use a long day length, I keep my light garden on 18 hours a day, 365 a year. More than 18 hours has deleterious effects. If your first frost does not happen until after Dec 15, you can let them get a few frosts, to give them their normal dormancy. Let us know, and well coach you on how and where to winter them.

If the leaves turn color and fall on their own, without getting a frost, the seedlings decided to go dormant based on environmental ques, then, keep them moist and put them in apot where if possible temperatures stay between 32 F and 40 F. While leafless light is not important, but keeping soil moist without being saturated is important.

The good news is, Amur maple is one of the hardiest, and most resilient species of maple to work with. You have a good chance of these pulling through the winter, and living to grow on for many years.

 

[Cypress187]

Welcome to the forum!

 

[Leo in N E Illinois]

Indoor bonsai - none of the maples, nothing in the genus Acer, will survive long term in under lights culture. Unless you have a super high tech system than includes a cold winter dormancy and blazing bright light.

Best species for indoor culture - Ficus - they grow best in "full sun" equivalent light gardens, but tolerate shade well, and can make great bonsai. Ficus retusa, microcarpa, pumila, benjamina, rubiginosa, and willow leaf types, all make good bonsai. Don't try the culinary fig, Ficus carica, indoors, it can be bonsai, but there are tricks you need to learn, not one for new to hobby. If you have a full sun equivalent light garden good enough for peppers, tomatoes and marijuana, you can keep ficus indoors all year round. If your light garden is lower wattage, like one for orchids, Ficus work well as a winter in the light garden, summer outdoors bonsai. This inside for the winter, outside for the summer pattern is they way most people do their indoor bonsai. But if your light garden is bright enough, you can keep them indoors year round.

Other good species for indoor bonsai include; Eugenia sp, Malpighia sp, Portulacaria afra, Nashia, Carmona, Wrightia, Nea, Ixora, Premna, Hibiscus, Bougainvillea, Clerodendron sp, and many more.

Some sub-tropicals can be done well in the inside for the winter, outside for the summer set up. One of the better ones is Pomegranate - Punica. also Gardenia, Citrus, and others.

If your light garden can be kept cool, less than 65 F at night all winter, the florist's azalea (hybrids based on Rhododendron simsii - bred for easy bloom in cool greenhouse) , gardenia, and other sub-tropical / temperate, cool winter species can work.

Juniper procumbens, and the dwarf Mendocino cypress are the only two conifers documented to be able to live long term under lights. Jack Wilke has an article on the American Bonsai Society website about growing these under lights. These two species are best only for the more experienced light gardener. They are not "easy" subjects, but your light set up for your seedlings sounds like you may have more experience than with light gardens than most, so you might be able to tackle them. I do recommend with initially sticking to deciduous or evergreen broad leaf species known to work for indoor light gardens. At least until you get some experience.

Finally, keep in mind. Most bonsai spend their training years in large nursery pots or grow boxes, and are many times larger than their finished size. If you want a twelve inch tall Amur maple, for most of its first 5 years it will need to be 5 feet tall or with 5 foot branches, just to thicken up the trunk. ONLY AFTER the trunk is as thick as it needs to be for your "finished" bonsai will you prune the tree down to something a little less than the 12 inch tall tree you set out to create. Actually it will be a series of let it get tall, then prune it short, let it get 5 feet tall again, then prune it short. This holds as a general rule for most broad leaf trees being trained for bonsai.

 

[sorce]

My Amurs have started putting on a lot since it got cool again...

These lil buggers night just have a fighting chance.

I'd leave em outside...maybe Styrofoam cover for winter..

Sorce