Course 01 · Checkpoint 3 of 3 · Growth through time · Final synthesis

Checkpoint 3: Growth through time (synthesis)

Germination, growth, seasonal cycles, and recovery, combined with the whole course in case-based decisions: when to act, when to look closer, and when to wait.

Covers:

As the final checkpoint, it also draws on ideas from the whole course.

Before you start

12 questions, each worth one point. Some ask for one answer; others ask you to select a stated number of answers.
For questions with several answers, each correct choice earns an equal share of the point.
Pass with 80%: at least 10 of 12 points.
Untimed and open book. Revisit any lesson while you work.
After you submit, you will see every correct answer with an explanation. Retake it as often as you like.

Checkpoint results are not connected to your account yet, so they are not saved.

Question 1 of 12Instructional example: a bonsai starter kit came with a packet of seeds labeled with the name of a temperate tree. Its directions said to soak the seeds overnight, sow them in moist, well-drained mix, and keep the pot on a warm, bright windowsill, and the owner did exactly that. The time the directions gave for seedlings to appear has passed, and nothing has come up.What is the best next step?
Put the pot in a refrigerator for a few weeks, since cold is what wakes tree seeds that will not sproutLook up what this tree's seed needs to germinate, then compare that with what these seeds have hadDiscard the tray and sow fresh seed, since these seeds have had the water, air, and warmth germination requiresKeep the mix wetter from now on and move the pot to a warmer spot nearby
Question 2 of 12Instructional example: a grower has seeds of two kinds of tree, neither of which needs any pretreatment. One kind is large and heavy, about the size of a hazelnut; the other is tiny and light, about the size of a pinhead. Both are sown in moist, well-drained mix at a suitable temperature and covered with the same layer of mix, several times deeper than the tiny seeds' packet advises.Which kind is more likely to come up, and why?
The large seeds, since their bigger store of food can carry each young stem farther through the darkBoth about equally, since a seedling feeds itself from the mix as soon as its first root has grownNeither of them, since a buried tree seed cannot germinate until light reaches it at the surfaceThe tiny seeds, since a small seedling has less to build and so needs less food to reach the surface
Question 3 of 12Instructional example, the windowsill juniper: a nursery juniper was sold in autumn as an “indoor bonsai.” For about four months since, it has stood on a warm, fairly bright windowsill. Its foliage is green but slightly dull, with no visible new growth. It is now late winter in a temperate climate: nights outdoors are around or slightly below freezing, a hard frost is forecast later this week, and spring growth outdoors is still some weeks away.What should the owner do about where the tree stands, starting now?
Keep it on the windowsill and add a grow light, since weak light is what is holding it backPut it outdoors tonight, so that it can start collecting the winter chilling it has missedMove it to a cool, bright spot sheltered from frost, so that it can adjust to the cold graduallyLeave it on the windowsill until spring, since moving a tree in winter adds a stress it does not need
Question 4 of 12Instructional example, the windowsill juniper: a nursery juniper was sold in autumn as an “indoor bonsai.” For about four months since, it has stood on a warm, fairly bright windowsill. It is now late winter. Its foliage is green but slightly dull, it has made no visible new growth, and its pot has a drainage hole. The owner wants to style it and repot it this weekend, and points out that its foliage is still green.What is the best decision about this weekend's work?
Postpone both, since it first needs suitable conditions and then weeks of normal new growthDo both this weekend, since foliage that has stayed green all winter shows it is healthy enoughRepot it this weekend, since fresh substrate will help it recover from its months indoorsStyle it this weekend but leave the roots alone, since styling on its own adds little stress
Question 5 of 12Instructional example, the windowsill juniper: a nursery juniper was sold in autumn as an “indoor bonsai.” For about four months since, it has stood on a warm, fairly bright windowsill. Its foliage is green but slightly dull, and it has made no visible new growth. The owner plans to check it every week or two through spring and keep dated photos.Which three observations, gathered over several checks, would together be good evidence that the juniper is ready for elective work such as styling? Select three.0 of 3 selected
Several weeks of regular fertilizer, which will have given it what it needs for the workThe calendar reaching the time of year when junipers are usually styled in your areaOne long, bright green shoot, even though the rest of the tree shows no new growth yetNew shoot tips lengthening from check to check, at about the pace normal for a juniper at that stageNew foliage of the color, size, and density typical of this juniper, with no thinning insideWhite, active root tips appearing at the drainage hole or along the edge of the pot
Question 6 of 12Instructional example, the trident maple in development: a healthy trident maple grows outdoors in a large training container in a temperate climate. It is the middle of the growing season, and the tree is vigorous, with strongly extending shoots and plump buds. The owner's goal is a thicker trunk. The owner lets one low branch grow freely, long and leafy, for a season or more.The diagram shows the maple, simplified, with that low branch left to grow. Where will the branch thicken the trunk most, and why?
Letter A, higher up the trunk, because a tree adds its new growth at the topLetter B, above the branch, because the branch's leaves send their sugars up toward the top of the treeLetter C, below the branch, because much of the sugar its leaves export moves into the trunk thereLetter C, below the branch, because its leaves pull extra water up through the trunk there, swelling the wood
Question 7 of 12Instructional example, the trident maple in development: a healthy trident maple grows outdoors in a large training container in a temperate climate. It is the middle of the growing season, and the tree is vigorous, with strongly extending shoots and plump buds. The owner's goal is a thicker trunk. The owner plans to let one low branch grow freely, and is also considering heavy root pruning, heavy branch pruning, and wiring with strong bends, all in one session now.Which plan best fits the tree and the goal?
Do all three now, then fertilize generously so that the tree has the energy to replace what it lostLet the low branch grow, and leave the other jobs for later, one at a time at a suitable stagePrune the roots and branches hard together now, keeping the crown matched to the smaller root systemDo all three now, since a tree as vigorous as this one has the reserves to recover from all of them
Question 8 of 12Instructional example, the trident maple in development: a vigorous trident maple grows outdoors in a large training container, and its owner let one low branch grow freely to thicken the trunk. A year later, in midsummer, that branch is long and leafy, and it spreads over a smaller branch below it that the owner plans to keep in the design. The rest of the tree is growing strongly, but this season the smaller branch has put out just two or three shoots, each only a few leaves long, and the leaves nearest the trunk have turned pale yellow, with some already fallen.What should the owner do?
Cut the small branch back hard, so that its buds are released and it grows stronger shootsLeave the long branch for its planned time, since the small branch will recover once it is goneFertilize the tree, so that the weak branch gets the nutrients it needs to grow strongly againShorten or remove the long branch now, so that light reaches the branch the design needs
Question 9 of 12Instructional example, the trident maple in development: in late autumn, after its leaves had fallen, one upper branch was wired to lower it. It is now midwinter, and the tree stands bare and dormant outdoors. The coils rest snugly on the bark, with no swelling beside them and no groove, and the branch does not yet hold its new position without the wire. The owner has read that wire must come off before it bites.What should the owner do about the wire?
Remove it now, since wire left on through a whole winter will have started to bite by springLeave it on, and check it once its new shoots have stopped lengthening in early summerLeave it on, and check it closely and often once growth resumes, as its buds swell in springLeave it on until next autumn, since snug coils need a full season of growth to start biting
Question 10 of 12Instructional example, the trident maple in development: after two seasons of free growth, the low branch the owner let grow has done its job of thickening the trunk, and its own base is now thick. The owner removes the branch, leaving a large cut on the trunk. The tree is vigorous.What will happen at the cut over the following years?
The cambium grows back across the cut face within a few seasons, and the wood beneath it comes back to lifeNew wood gradually replaces the damaged wood, until the trunk is as sound inside as it was before the cutThe cut face stays bare, since a tree makes new wood only behind its growing shoot tips, not at a woundThe tree walls off the damaged wood and slowly grows new wood and bark over the cut from its edges
Question 11 of 12Instructional example: a different trident maple was healthy until last summer, when a hailstorm stripped most of its leaves. It pushed out a fresh set within weeks. This spring, in the same bright spot, its new shoots are short and its leaves small, well below what healthy trident maples nearby are making. The owner wants more branching and plans to remove the tips of its new shoots now.What is the best decision?
Remove the tips now, since taking off a tip releases the buds below it and builds branchingRemove the tips and most of the leaves, so that all of the tree's sugar goes to the buds belowRemove the tips now, then watch over the next few weeks to see how many buds respondLet its shoots grow unpruned until its growth is back to normal, since their leaves rebuild its reserves
Question 12 of 12Instructional example: a mature crabapple bonsai, a temperate flowering tree, grows outdoors in good light. Late last summer, while its owner was away, its root zone dried out completely for several days, and it lost many leaves and, most likely, many fine roots. This spring it flowered heavily, but its new shoots are short and its leaves small, well below what it made in past years. Dozens of young fruit are now swelling along its branches, and the owner would like to keep them all for autumn display.Which plan best supports the tree's recovery this year?
Keep all of the fruit, since fruit is mostly water and costs the tree very little of its sugarShorten its new shoots, so that the tree has less new growth to supply alongside the fruitKeep all of the fruit, since a tree that flowered this heavily must have reserves to spareRemove most of the young fruit now, so more of its sugar goes to shoots, roots, and reserves

0 of 12 questions answered