Why are all of the gardens yellow?

I really don’t know what to say with this one, things seem to dry out twice as fast in Autumn, when the rain starts to come more frequently. It is the weirdest thing. I don’t know if, because it is getting cooler, we stop watering as much, and assume the garden will be fine? Or if the plants are suddenly thirstier?

Who knows. Probably very garden-specific!

This week we started talking about how to diagnose issues in a crispy plant, and how to nurture these poor dry babies back. That part was a quick conversation, however, because unless it is midsummer, the reason plants go yellow and brown is rarely due to water.

This potted plant is less than a year old. Some people are happy to nurture it through winter, and have a similar sized plant next summer. There isn’t a huge difference in buying the plant new in Spring, or nursing this one, because they will end up about the same size when flowering. So… do you want a cut-back struggling plant in Winter, or something else in it instead? The difference is about $20, and entirely up to the owner.

This particularly crispy bog rosemary is entirely my fault- you can see from the wilt in the groundcover plants that I haven’t watered it enough and the brown is due to dieback- in cases like this, a long soak and regular watering until winter, and then cutting the plant back in May might save it.

Sometimes high winds are unpredictable and plants that have lived happily in one spot can snap. Then suddenly.. half of the plant is mysteriously dead? Is it drought? Nope. The only thing for it, is to cut the damaged branch completely, cleanly, below the break. Unfortunately for this bush, it will halve in size, but the dead part is not salvageable and will not look better…

This is a coleonema, which does not regenerate from heavy trimming, so needs regular trimming or it will get bigger and bigger… and also has a tendency to snap in high winds.

Ah, good fun. Now, do we plant a tiny plant to fill in the space, knowing we can’t get any large sizes of this variety? I would probably want to chuck in something taller, like a specimen tree, and square off the hedge much earlier, because waiting for 15 years for the plant to get this size does not sound like much fun.

Sometimes the dying leaves are of real concern. If you have seen us pulling off manky-looking leaves on plants, it is probably because the problem is not really an issue, and more of an aesthetic choice, like the plant below.

This Coprosma repens has sucking insect damage, which you can see because the middle of the black spots are brown- cell damage. This tree is actually relatively happy, so if the spots are obvious or a bother, we will just remove those leaves.

Yellowing leaves are only really an issue if they are new leaves. The coprosma above has one, old, yellow leaf. This leaf is at the end of its life so it will either naturally fall off in the next month, or we can pull it off as we go past. Yellow leaves are no issue unless the whole plant is yellow, as opposed to leaves further down the stem.

As an aside, yellowing citrus trees are also an issue throughout winter. Sometimes this is because they can’t uptake enough nutrients through the roots, sometimes there are enough nutrients in the soil, sometimes there aren’t. A foliar feed of something higher in nitrogen (powerfeed is a great liquid, nitrogenous fertiliser) will help the leaves darken back to a healthier green.

Sometimes plants look especially bad and dry this time of year, but they need their annual cutback. Plants like this are usually perennials, which means they will flower next year, but this year’s flowers need to be cut right back.

This red campion looks like an absolute mess, but in reality it will be cut down to ground level, and look great until next year.

On the other hand, some plants such as roses show yellowing and brown leaves as a sign of fungal disease, as seen below. Buxus and roses are classic plants where if you see a browning off part, it is better to remove it entirely from the garden to stop its spread. We are fairly brutal with rose leaves, and spray the remainder with seaweed fertiliser to protect the remaining plant. Buxus which has fungal issues needs an entire treatment plan. I have come to believe that if you are at the point of needing to cut whole areas out, you should wait until mid winter and cut the entire hedge down lower and begin an aggressive seaweed-horticultural oil spraying regime to knock the remaining spores on the head. We had a great gardening session the other week at a client’s, when we realised that the horrible damage to her buxus wasn’t from a fungal issue, but a cat spraying on it! Just as hard to treat, I worry…!

At the end of the day, if leaves are starting to die, or parts of the plant are dying back, you need to weigh up aesthetics against the health of the plant. If there is damage or disease, remove the affected parts as soon as possible. But if everything is just looking a big sad because of Autumn, see how long you can leave it before overfilling your compost heap with the trimmings. The plant will pull as many nutrients out of the dying area as possible, before the dying part is crispy and brown, so it is better off hanging onto the dead part as long as possible.

Thanks for reading everyone! Ensuring every staff member talks about our weekly focus has been so great for our team in so many ways. I have really enjoyed our write ups so far! Have a fantastic Easter weekend :)