"Worn-out plantings"

Many plants need rejuvenation after a few years.
Sunday, 22 August 2021     

Agapanthus praecox in my driveway

Maybe it's because I have been spending more time in my garden lately than I have for many years, but I am really noticing that lots of my plants are past their use-by dates or else in serious need of attention! Trees and evergreen shrubs just seem to get better and better as each year passes, but other sorts of plants demand rejuvenation after a while. It's sobering to realise just how long it is, for example, since the Agapanthus along a path in my garden have been there without ever being divided (the answer being at least 15 years): no wonder they are overcrowded, growing all over the path and not flowering that well these days!

Many evergreen rhizomatous clumping plants like this do get to a point where they have to be dug up, split up, and replanted into soil with some compost added, to restore them to their former glory. Apart from the Agapanthus, we've tackled Clivia in recent weeks, and others are on the to-do list, including false cardamom (Alpinia nutans), giant Liriope and many of my bromeliads. I was pleasantly surprised to see that the Clivia I moved about a month ago are starting to flower, as I feared the trauma might have meant no blooms this year. The work is arduous, but the results are worth it, and the spare bits are very useful for filling bare spots in the garden, which is very satisfying.

Smaller herbaceous perennials and spreading groundcovers also need to be dug up and separated every so often to maintain vigour. Somehow, I just never seem to get around to this for some of them, and another year rolls past, with the result being congested clumps that just don't perform very well. Sometimes they just completely fade away. Some of these that I have been tackling lately include perennial Phlox, perennial Aster, Lychnis coronaria, Geranium macrorrhizum and Lamium maculatum. As with the larger perennials, I dig plenty of compost into the area where I replant them. I don't grow many traditional cottage garden plants much nowadays, but I love these ones, as they do alright in Sydney and are the vestiges of the dream I once had of creating a gorgeous English-style garden, which alas, never came true.

Bulbs, corms and tuberous plants also amazingly clump up over time, and before we know it, they aren't doing so well anymore. Again, the task of dividing them seems to get put off from year to year, but this time round, I have no excuse! So I have been busily thinning out Dahlia and Canna, and plan to divide my snowflakes, jonquils, starflowers and Watsonia as soon as the leaves die down after flowering is complete. Spare bulbs can be stored in netting bags over summer in the garage - or replanted straight away. I sometimes pot up spare ones to take to the local garden club sales table - but, sadly, who knows when we will be meeting again? How I miss my gardening friends!

Smaller shrubs and bushy perennials are other types of plants that seem to get to a point where they are no longer very productive after a few years, and we need to remember to take cuttings of them so we can start again with a fresh, robust specimen. The ones most in need of this treatment seem to be the warm-climate types, such as Abutilon, Pentas, Plectranthus, marguerite daisies and many shrubby Salvia, especially the 'Wish' series, Salvia microphylla and Salvia x jamensis cultivars, Salvia splendens, Salvia fruticosa and Salvia 'Van Houttei'. Those Salvia that are actually herbaceous perennials, as mentioned in a recent blog, which die back to the ground each winter then re-emerge with fresh new stems each spring, don't need to be renewed from cuttings in this manner but every few years, the woody, basal mass benefits from being divided or thinned a bit. I have done this with my Salvia 'Joan' this year, as it hasn't been doing very well over the past years - no surprise given it was planted in its spot probably 20 years ago!

Some climbing plants seem to get to a point when they are hopelessly woody and seemingly moribund, when they get very old. One drastic solution can be to cut them almost to the ground and see what happens. in some cases, they will sprout again and do well.

With the exceptional weather we have had in Sydney this weekend, attending to some of these jobs has actually been a sheer pleasure. And I am sure the plants have appreciated my efforts!

 Reader Comments

1/6  Simon - 2126 (Zone:10 - Warm Temperate) Monday, 23 August 2021

Hi, Do they really need dividing or is it more that the ground needs refreshing with new compost, fertilizer etc. All the best, Simon Great to hear from you, Simon. I do think it is both the need for division and the replenishment of the soil. Especially for herbaceous perennials, the centre of the clump often becomes unproductive and needs to be discarded and the crowding of the other elements of the clump impedes good performance. Deirdre

2/6  Margaret - 2122 (Zone:10 - Warm Temperate) Monday, 23 August 2021

Like you, I am taking advantage of giving the garden a 'make over'. So much work to do: have cut back plectranthus, pentas, some abutilons and my clematis; also divided perennial asters, rhizome begonias (a good time to do this, as cuttings/pieces take readily), and also some clivias. Clivias are accommodating, surviving not being planted immediately. After the good rain this week, these jobs are a lot easier with moist soil! Deirdre

3/6  Carolyn - 2125 (Zone:10 - Warm Temperate) Tuesday, 24 August 2021

I've also been doing a lot of rejuvenation in the garden. Having all this extra time at home means I've been able to just stand back and look more critically at some of the shrubs. I've taken out a few which, although attractive when they flower, are just too much work and are unattractive for most of the year. It's good having this unhurried time to evaluate our plants more. One type of plant I forgot to mention in the blog is those deciduous shrubs that grow from canes coming up from the ground. These can get really crowded over time if not removed right at the base every so often. These shrubs don't flower so well then. I am really going to hack at my deutzia this year as it has gone off over the past few years. I will wait till after it flowers, though! Deirdre

4/6  Shaun - 2075 (Zone:10 - Warm Temperate) Tuesday, 24 August 2021

Just catching up on your most recent blog Deidre, I realise that as well as your gardening tips, I doenjoy the flow of your descriptive writing, 'in 'English as she should be spoke', a memory of my Dad. Glorious rain, at last, soak on for a day or two I say. Thank you Deirdre, Shaun Thanks for your kind comment, Shaun - that means a lot to me. Deirdre

5/6  Valerie - 2121 (Zone:10 - Warm Temperate) Tuesday, 24 August 2021

Thanks Deirdre for this timely reminder. The weather is cool enough to really do some work with the mattock, pruning saw etc. Good luck with the Agapanthus. My mother used to call these 'the elephants of the garden'. I've planted them to fill quite a few areas and interrupt water flow, especially under fences. Also thanks for including the snowflakes. They seem to be tough survivors. I'm waiting on the Bluebells now while enjoying the Freesas. I used to take aggies so much for granted but I am more appreciative now. They are so tough and are even good in a shaded spot for lush greenery, though they don't flower so well. Sometimes I get a few blooms from them though in such areas! Deirdre

6/6  Sue - 2074 (Zone:10 - Warm Temperate) Tuesday, 24 August 2021

Very nice blog and good advice. After the rain we have had today it will be easier to lift and divide so I am inspired to get going. I did divide/separate my Kniphofia 'Winter Cheer' last year and it paid off this winter with lots of lovely flowers. Gosh I haven't divided mine for years! I must put that task on my list! Deirdre

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