Choosing healthy, useful starting material

Late spring at a garden center in the course's example climate (an instructional example). On the outdoor sales bench, compact junipers in black nursery pots cost little. Indoors, on a gift shelf, a ficus with a thick, curving trunk sits in a glazed pot, its tag reading only “Ficus.” In the bonsai area out back, a trident maple in a wooden box carries a high price, its trunk already thick. On the clearance bench, a juniper like the ones on the sales bench is marked half price. And among the young plants, a Chinese elm with a stem as thin as a pencil costs least of all.

Any of these could be someone's first bonsai. But the cheapest is not automatically the best buy, the most finished is not the easiest, and the bushiest is not the best material. Choosing well comes down to two questions, which this lesson takes in turn: how far along is each tree already, and is it healthy enough to start with at all?

Every starting tree is somewhere on a long path

Making a bonsai from scratch runs through three long phases, roughly in this order and with plenty of overlap:

1. Grow the trunk and roots. The tree grows freely so its trunk thickens and its roots spread. This is the longest phase.
2. Choose and build the main structure. The trunk is often cut back, a new top grows, and the few main branches the design will use are chosen and grown out.
3. Refine the fine branching. Repeated trimming divides each branch into many short twigs, usually once the tree is in a bonsai pot.

After that comes care that never ends: keeping the tree healthy and in shape, every year.

Starting material is sold at different points along that path, and what is already done is largely what you pay for.

• Seeds, which you sow and raise yourself (Course 01, Lesson 11). Every phase is still ahead.
• Liners, young plants such as seedlings or rooted cuttings, sold small for growing on. Very cheap, with only a small start on the trunk and roots.
• Nursery stock, the ordinary plants a garden center sells, grown to look full in a garden rather than for bonsai. Affordable, usually healthy, and partway through the first phase: plenty of branches, but a thin trunk, a root flare (where the trunk widens into its main roots) often buried in the pot, and roots that may circle the pot wall.
• Pre-bonsai, material grown for bonsai, usually by a specialist nursery, with the trunk and surface roots developed and often a first cut made. The first phase is done and the second begun, and the price reflects those years.
• Developed bonsai, trees with years of design and refinement already done. The most expensive start, and the one that needs the most skill to keep as it is.

How far along a tree is says nothing about its health, which you check separately on every tree.

In How far along is it already?, every row under Starting point is drawn against the same Now line: the solid pieces to its left are Done before you buy it, and the dashed pieces to its right are Still ahead of you. Start with Seed and press Play to watch a trident maple grow through the whole path, or step through it with Next and Back. Then choose Nursery stock, Pre-bonsai, and Developed bonsai in turn, and compare each row and its card: Relative cost, Main risk, and Who it suits.

The rows make a staircase: the further along a start, the more of its row sits left of Now, and the higher its relative cost, from Lowest for a seed to Highest for a developed bonsai. Phase 1, growing the trunk and roots, is the longest piece, which is why seeds and liners are cheap and pre-bonsai is not: the years are the price. Nursery stock sits partway through phase 1, bushy but thin in the trunk; as its card says, lots of branches are not the same as useful structure. And every row, the developed bonsai's included, ends in the same dotted tail of Ongoing care.

The drawing follows a trident maple. A juniper, which rarely grows new shoots on bare older wood (Course 01, Lesson 12), takes a different route and is not cut back to a bare stump.

Mall bonsai: a way of selling, not a stage

One more kind of starting tree is defined by where it is sold rather than how far along it is. Mall bonsai are small trees sold ready-potted in supermarkets, malls, and gift shops, often labeled “indoor bonsai.” Many have been shipped a long way and kept in dim shops with irregular watering, and many carry a vague or wrong label and sit in pots with glued stones or no drainage hole. The gift juniper from Lesson 2 is typical: a temperate tree that belongs outdoors, tagged “INDOOR BONSAI,” in a glazed pot with no drainage hole and pebbles glued into a hard crust.

None of this makes mall bonsai worthless. Many have trunks already thickened or curved, and a healthy one can be a fine first tree. It simply needs the most careful inspection of any starting material, and often a few corrections at home (Lesson 7).

Collected trees: permission first

A collected tree, called yamadori in Japanese (roughly “collected from the mountains”), is dug from the wild or from long-established land, such as an old hedge or field, rather than grown in a nursery. Old collected trees can have trunks no nursery could grow in a lifetime. For this course, only the ethics matter:

• Collect a tree, or buy a collected one, only with the landowner's permission and any permits the law requires. In parks and nature reserves, digging plants is usually forbidden.
• Some species are protected by law, and digging them is illegal.
• Ask a seller who collected the tree, where, with what permission, and how long it has grown in its container since.

A newly dug tree has lost much of its root system and needs years of specialist aftercare, so it is not a first tree. How to collect is beyond this course.

Trunks take years, and small pots slow them down

The trunk is the slowest part of a bonsai to build and the hardest to change later. It thickens by secondary growth: each year the vascular cambium lays down a new ring of wood, built from sugars the leaves make (Course 01, Lesson 12). A small pot holds few roots, few roots support only a modest canopy, and every trim removes leaves that would have fed the trunk, so a potted, clipped tree adds only narrow rings. Growing freely in the ground or a large container, its roots spread, its canopy grows large, and the rings widen.

So a thick trunk is grown first and shaped later, sometimes with the help of a sacrifice branch (Course 12, Developing Bonsai from Starting Material). For a fast-growing broadleaf such as a trident maple or a Chinese elm, a useful trunk can take several years in the ground; a slow, compact juniper takes far longer, and in a small pot any tree takes much longer still. That is the hidden cost of a cheap start: seeds and liners cost little money but many years. And for nursery stock, the trunk in its nursery pot is largely the trunk you have for now: style the tree as it is, or grow it on freely for years first. Clipping for shape and growing for thickness pull in opposite directions.

Check health before price

A tree's stage tells you what you are buying; its health tells you whether to buy it at all. One visit is only a snapshot, and green foliage alone is weak evidence (Course 01, Lesson 14), so look for several signs that agree. You need only your eyes and hands, a sheet of white paper, a chopstick, and, if you have one, a hand lens. Ask before you handle a tree or lift it from its pot; many sellers will let you, or do it for you.

Foliage, buds, and new growth

Judge the foliage against what that kind of tree normally looks like at that time of year, the standard Course 01 used for vigor. In late spring, a healthy juniper is dense right into its center, with soft, paler tips; a healthy trident maple has full leaves and strong new shoots.

Some normal seasonal looks mislead: many junipers turn bronze or purplish in winter, deciduous trees are bare from autumn to spring (Course 01, Lesson 13), and junipers shed some old inner foliage each year, mostly in autumn. When nothing is growing, look at the buds and twigs: plump, firm buds and twigs that bend rather than snap are good signs; dry, shriveled buds suggest a weak tree or a dead shoot.

The warning patterns are browning that spreads over much of the tree, dull or grayish foliage with no new growth when the tree should be growing, and dead, brittle tips on many branches (dieback). Yellow leaves on a broadleaf are harder to read: a few older leaves yellowing after a move into dim light is common, but root and pest problems can start the same way, and a symptom is not a diagnosis (Course 07, Tree Health and Diagnosis). And because a conifer can stay green for weeks after its roots die, good foliage never clears a tree on its own.

Pests and their traces

Most pests on a garden-center tree are small and hide in the same places: leaf undersides, the angles where leaves meet stems, the inside of dense needle tufts, and soft new tips. Look there for:

• Webbing: fine silk among needles or leaves, often with dull, speckled foliage nearby. It suggests spider mites.
• Sticky residue: a shiny, sticky film on leaves (honeydew), left by sap-feeding insects such as aphids, many scale insects, and mealybugs. Black sooty mold can grow on it.
• Bumps: small brown or gray raised ovals along stems and leaf midribs that do not move and do not brush off easily. They are typical of scale insects.
• Cottony patches: white, waxy tufts in leaf axils and along stems, often mealybugs.
• Clusters of small, soft insects on shoot tips and young leaves, usually aphids.

Then hold the white paper under a branch and tap the branch sharply: tiny specks that move are often spider mites. These are clues, not diagnoses; Course 07 covers identification and treatment. A few aphids on a vigorous tree are minor, but pests spread over much of a tree, or on a weak one, are a reason to walk away. Whatever you buy, keep it apart from your other plants for its first few weeks (Lesson 8).

Trunk, branches, and bark

Look first for soundness. Bark should be firm and intact, though some bark is naturally loose: junipers shed their outer bark in thin, stringy strips, and Chinese elms and older trident maples flake in patches. What matters is what lies beneath. Bark that lifts away to show brown, dry tissue, or a sunken, discolored patch, suggests the living layer under the bark has died there (Course 01, Lesson 3), and deep cracks or fresh splits open the wood to decay. Old pruning cuts should be closing with a rounded roll of woundwood (Course 01, Lesson 14).

Then look for usefulness, starting with the trunk, because it is the hardest part to change. Does it narrow from base to top (taper), and does it have some movement, or is it a straight, even pole? Then the branches: a few that start low, at useful heights, give you real choices for a first design. Their number matters much less. Nursery stock is grown to look full in a garden, so it often has dozens of thin branches along a thin stem, most of which a first styling will remove (Course 10, Wiring and First Styling).

The base: root flare and graft union

The root flare is where the trunk widens and spreads into its main structural roots (Course 01, Lesson 2). A visible flare that spreads evenly in several directions makes a bonsai look stable and old (bonsai growers call the visible spread of surface roots nebari), and it is one of the slowest features to create, so it adds a lot of value.

In nursery pots the flare is often buried, because young trees are potted up, sometimes deeper, and topped up with mix. Probe gently with a chopstick or a finger close to the trunk until you meet the widening roots. A buried flare is common and, in the short term, not a health problem; it can be uncovered gradually later (Course 11, Repotting and Root Development). Note how deep it is and whether the roots spread evenly or all run one way.

Also look for a graft union, the join where a shoot of one plant was grafted onto the roots and lower trunk of another. It shows as a swelling, a step in thickness, or a change in bark, usually low on the trunk. Many cultivars, including many Japanese maples, pines, and flowering trees, are grafted. A sound union does not harm the tree, but on a bonsai it can stay visible for life: a neat one near the soil matters far less than a bulge partway up the trunk.

The root zone

The roots decide whether a tree can recover from anything else, so this check matters most.

• Firmness. Rock the base of the trunk gently: the root ball should move with the pot. A trunk that wobbles in the mix has few roots holding it, because it was potted up recently or because roots have died. Ask, and look closer.
• Moisture. Lift the pot and push a finger into the mix: neither bone dry nor soggy. A root ball that has shrunk away from the pot wall has dried right out, water poured in runs down the gap, and many of its fine roots have probably died (Course 01, Lesson 14). A pot that stays heavy and wet with a sour or rotten smell suggests roots short of oxygen (Course 01, Lesson 7). Healthy mix smells earthy.
• Root tips. With the seller's permission, ease the root ball out of its pot. Plenty of pale, plump root tips at the edge show roots that are growing (Course 01, Lesson 2). Dark, shriveled, or mushy roots with no tips anywhere are a bad sign.

A pot so full of roots that they circle the wall and mat at the bottom is root-bound. A mildly root-bound nursery tree is common and often healthy, and roots poking out of a liner's drainage holes simply mean it is ready for a bigger container. A badly root-bound tree, though, dries out fast. Circling roots are dealt with at repotting (Course 11), not at the bench.

Label and provenance

A full scientific name on the tag lets you look up the tree's needs (Lesson 2); “Ficus” or “juniper bonsai” alone does not. Then ask about the tree's provenance: where it came from and how it was grown. A tree grown outdoors at a nursery nearby has already lived through local winters and is used to outdoor sun. A tree from a heated greenhouse or a shop shelf may have soft leaves grown in weaker light and little cold acclimation (Course 01, Lesson 13), so it needs a careful transition to its new home (Lesson 3). An imported tree may have grown in a quite different climate, so ask how and where. Origin matters for hardiness too: trees of the same species raised from seed collected in a warmer place can be less cold hardy than those from a colder one.

Match the material to the goal

A healthy tree must also be useful for what you want to learn, able to live in the place you have, and within what you can spend and wait. Settle four things before you shop:

• Your goal. Care and a first styling this year? A thick trunk over many years? A tree for one particular spot?
• Your place. What your site profile says it can offer (Lesson 1), especially light (Lesson 4) and winter cold. A temperate tree needs its outdoor seasons; only tropical and some subtropical trees can live indoors, and then only in strong light (Lesson 3).
• Your budget, with something left over for a pot that drains and a few basics (Lesson 7).
• Your patience. How many years you will wait before there is something to style.

For a home with no outdoor space, such as the bright window, the place alone narrows the choice to trees that can live indoors, such as a tropical ficus, inspected with extra care. (The bright window faces south, the sunny side in the Northern Hemisphere; in the Southern Hemisphere, swap north and south.)

In Inspect five starting trees, you meet the five candidates from the start of this lesson. Under Tree, choose one, from A · Nursery juniper to E · Chinese elm liner, and press its six buttons, from Foliage to Label and source; each finding is tagged Good sign, Worth knowing, Check closer, or Warning sign. Inspect at least A, B, and D in full, comparing A with D, the same kind of juniper at two prices. Then, under Choose a tree for each goal, take each Goal in turn, read its Assume: line, and choose a tree, or Keep looking.

Tree D was a Walk away for every goal: a dried, shrunken root ball, brown inner foliage with no new growth in late spring, dead tips, and a history of missed waterings are four warning signs that agree, and no discount buys back dead roots. Tree A, the same kind of juniper for a little more, had five good signs and one thing worth knowing: its buried flare, a feature to deal with later rather than a fault. Tree B was mostly Check closer: not bad news, but unknowns to settle before you trust it.

The goals gave the same trees different answers. On a small budget, only A fit: healthy, cheap, with low branches to style, and wanting the outdoor sun you can offer. For a thick trunk, the pre-bonsai maple fit if you can pay for its years, and the elm liner if you will grow those years yourself. For the window, only the ficus could work, and only with conditions; waiting was also sensible. And price was no guide to health: the cheapest and the most expensive trees were both healthy, and the discounted one was in decline.

Two healthy, inexpensive trees can teach you more than one expensive one: you can compare them, style one while the other grows freely, and treat a mistake as a lesson rather than a disaster. As for where to buy: garden centers sell nursery stock; specialist bonsai nurseries sell liners, pre-bonsai, and developed trees, and usually know their trees' names and histories; and local bonsai clubs often hold sales and know which trees do well in your climate.

Before you pay