Selim

The genuinely serious problem with saving your own seed potatoes is not size at all — it is disease.

Potatoes accumulate viruses through the season, carried mainly by aphids, and those viruses pass into the tubers. The plant may look fine and still be carrying several. Replant those tubers and the next generation starts already infected, and the crop declines noticeably over a few years.

This is why certified seed potatoes exist and why they are grown in specific regions — often cooler and windier places where aphid pressure is low — and inspected. It is not a marketing arrangement; it is the actual reason the crop stays productive.

So for the fictional case, with no aphids and a closed system, saving tubers indefinitely is fine. In a garden, refreshing your seed stock every few years is the thing that matters, and it matters far more than which size you replant.

There is a real and growing use for true seed that is worth knowing about, though, because it addresses the problem you were trying to solve.

Seed carries far less disease than tubers. The viruses that accumulate in a tuber line generally do not pass through true seed, so seed-grown crops start clean. In places where certified seed tubers are expensive or hard to obtain, and where storage conditions are difficult, growing from true seed is a serious approach rather than a curiosity.

There are also modern hybrid true-seed varieties bred to produce reasonably uniform plants, which removes much of the lottery problem. They are a relatively recent development and worth looking for by name if this appeals.

The trade is time: seed-grown plants usually spend their first season producing small tubers, which you then use as seed the following year.

Both are right about different things, and the variable that reconciles them is timing.

The competition claim is true — weeds do take water, nutrients and especially light. But crops are not equally vulnerable throughout their lives. There is a period, usually early, when competition does most of the damage, because a small seedling shaded by a fast weed never catches up. Once the crop has closed its canopy and is shading the ground itself, weeds underneath it cost very little.

So the practical rule is not "weed constantly" or "do not weed". It is: keep the bed clean while the crop is establishing, and relax afterwards.

That single distinction resolves most of the argument, and it also explains why experienced gardeners look casual about weeds in August and are ruthless in May.

Two cautions on the barrier, since it is easy to do badly.

Do not put glue or grease directly on young bark. Wrap the trunk with a band of paper or fabric first and apply to that. Direct application can damage bark on a young tree.

Check for bridges. Ants will use a long grass stem, a low branch touching a fence, or a leaning weed to bypass the band entirely. Clearing a small circle around the trunk is part of the job, and it is the reason most barriers that appear not to work actually failed.

Also worth checking there is no aphid colony below the band, in which case you have simply trapped the farmers with their herd.

One expectation to adjust: frogs are not a mosquito control strategy.

Adult frogs eat a broad range of invertebrates and are not particularly focused on mosquitoes. What genuinely eats mosquito larvae is the rest of the pond — dragonfly and damselfly larvae, water beetles, backswimmers — which arrive at a pond by themselves, often within weeks.

So the pond is the right answer to your original problem, and the frogs are a bonus rather than the mechanism. Meanwhile the highest-value mosquito action is unglamorous: find and empty every container of standing water in the garden, since that is where they actually breed.

Which is why the actual answer is the awkward one: the tree has to be dealt with, and it is not yours.

Approaching the neighbour works better than people expect if you frame it correctly. Most people do not know what they have. "That grew from a weed and it is a species that damages foundations and drains, here is the identification" is a very different conversation from "your tree annoys me". The risk to their own building and drainage is usually the part that lands.

It is worth being clear that the general legal position in many places allows you to cut growth that crosses onto your property, and that this does not extend to entering their land or killing their tree — and that the specifics vary a great deal by jurisdiction. If it comes to that, the question is one for somebody locally qualified rather than for a forum.

Document everything meanwhile: photographs with dates, where suckers appear, any damage. That record is what makes any later conversation, formal or not, straightforward.