Tag: fertilizing

Challenging Common Rose Planting Advice

At the risk of seeming foolish, I’m going to court controversy, and attempt to debunk a piece of gardening advice so commonplace that it’s taken as gospel truth. It goes like this:

When planting a rose, dig a much larger hole than the pot size, and then amend the soil heavily before back-filling around the new plant.

I’ve seen different versions of this. Some say a hole 2 times as wide as the original pot. Some say wider. As to depth, many articles advise to dig just the depth of the pot (which makes sense to me), but others say to dig 18″ or 24″ no matter the pot size. In any case, there are any number of recommendations about how to amend the soil: bone meal, kelp meal, compost, well-rotted manure, alfalfa pellets, granular fertilizer, chelated iron, bagged potting mix, feather meal, and maybe even the kitchen sink!

I disagree with nearly all of this, and I’ll tell you why – first in this video, then in written detail below:

To recap my reasoning:

  1. The very most important thing to establishing a newly planted rose is to encourage the roots to grow outwards and downwards into the surrounding soil.
  2. The roots being firmly anchored down into the undisturbed native soil becomes really important over the winter, when the shrub is subjected to the additional weight of snow/ice and force of winter winds.
  3. The “boundary” between your improved soil and the surrounding unimproved soil becomes a barrier for roots and the natural drainage of water. Just common sense: if the soil inside your planting hole is so much richer, wouldn’t the plant favor root growth there instead of anchoring to the surrounding soil?
  4. I’ve learned it’s safer to err on the side of less fertility when establishing new plants – both here on my farm, and in my job as a grower. This isn’t a drag race… you don’t need to pump in the nitrous oxide!
  5. Back to stability: all those organic components mixed into the soil will eventually break down, leaving a pocket of less dense soil in the improved planting area.
  6. All of the soil improvement you could hope to achieve by the big hole method can be more safely and evenly applied by subsequently feeding your soil from the top down. Topdress with those organic amendments, add a mulch to the surface, and let the worms and soil life do the rest. They’re really good at the soil-improvement business!

Plus, less digging. Nuff said.

Avoid These 3 Things To Help Your Roses Survive Winter

Roses are built to survive winter

Don’t treat your roses like they’re the fancy dinnerware of the garden. Most are descended from tough, northern climate species, and they’re well prepared to get through the cold of fall and winter – at least in the mild-to-moderate climate of the Fraser Valley. Some of the “special care” that gardeners offer their roses in the lead-up to winter can, in fact, be detrimental to their survival. Don’t kill your roses with kindness! Avoid these 3 mistakes to give your roses a fair chance to survive:

#1: Late season pruning

Lock those pruners and back away from the rose… slowly. It may be tempting to give your roses a good cleanup going into the fall and winter. The leaves are yellowing and falling, the flowers are spent, and the stems are untidy – if not downright overgrown. You might think that your rose has a better chance if you cut it down lower, and send it into the winter with clean stems. You’d be wrong. Let me say this unambiguously – before winter is the wrong time to do structural pruning on a rose.

Why? Look at what winter damage on a rose looks like:

The stems are blackened at the top end – the most exposed tissue to the cold and drying winds of winter. The length of cane damaged will depend on the hardiness of the rose (many varieties have some sub-tropical genes bred in to promote reblooming) and the severity of the winter. In a mild winter, it may be only a couple of inches – in a severe winter, I’ve seen the damage exceed 18 inches!

Now I ask you: if you left your rose unpruned at 3 to 4 feet of height, and you lost 18 inches of stem in a severe winter, how would you feel about it? Not bad, probably. You were going to prune for shape and structure in the spring anyhow. Now how about if you pruned it back low  before winter – say to 18″ from the ground? If the winter damage reaches all the way back to the crown, it’s game over.

As an added advantage to leaving your rose a little untidy over the winter, birds and other wildlife depend on the rose hips and canes for food and protection.

I will add an exception now, just for completeness: there’s no bad time to remove dead or diseased wood from the rose. Also, if there are a few stems that have grown well above any support, and you know that they’ll just blow around and break in the wind, go ahead and prune them back to a reasonable length.

#2: Late season fertilizing

This one is a little counter-intuitive. It seems like a good idea to supply your plants with all the nutrition they need before the harshness of winter. A late-summer or fall application of fertilizer, however, can send your rose the wrong signal.

Those sub-tropical semi-evergreen rose genes I mentioned in passing come back into play here. Some of the best reblooming roses have a tendency to push new growth late in the season. They’re opportunistic growers. If the weather suits them, they’ll keep growing. As of today, November 19th, I still see a dozen or so roses in my garden cheerily flowering and sending up new growth.

In addition to mild weather, they’ll also grow in response to ample feeding and to heavy pruning.

That soft growth has no chance of hardening-off before winter. By far, you’re better off leaving the fertilizer until spring. Here on the rose farm, I stop feeding my outdoor roses in August.

#3: Deep Winter Mulch

The practice of hilling soil or mulch over the crown of a rose is a carryover from advice given to gardeners in very cold winter regions when trying to overwinter roses that are not well suited for their climate. It doesn’t apply well here, and from what I’ve read, it should be applied with caution even in colder climates. Read this article from the University of Illinois Extension for a good description of these methods. The emphasis is on not trapping moisture at the crown of the rose.

I don’t winter mulch anything. We take -10 celsius with heavy outflow winds, and my losses have been minimal. I’m crossing fingers and knocking wood as I write this, but I’m also quite sure that in our wet climate, anything that could hold water against the crown of my roses is not worth the risk.


For those who are more visual learners, here’s a video I made on the topics discussed above:

Spring tidy and fertilizing

In the succession of flowering times for garden shrubs, the Forsythia comes early, and perhaps because it’s such a bright (or even objectionable, depending on who you ask) shade of yellow, rose growers use it as a reminder to get out there and prune their roses. If you lack a Forsythia, you definitely use the more attractive red-flowering currant here in the Lower Mainland, and it wouldn’t much change your timing. I snapped a picture of my inherited Forsythia this week… and as you can see, I’ll never miss pruning time:

The red/pink flowers in the foreground are quince (Cydonia), another shrub you could use to get nearly the same timing – it’s probably a week behind in my garden.

The reason many rose gardeners wait until this part of spring is that it coincides with roses being ready to break dormancy. By this time, winter kill on the canes (evidenced by black tissue higher up the extremities of your roses) will be apparent, and you will probably be able to see some of the buds swelling.

How to prune them? It depends on the rose, and it depends on what you want. This is your first chance of the season to influence your rose. Cutting harder usually means that the rose will respond with a number of strong shoots from the base, and will result in more flowers this season. A lighter prune allows the rose to grow and harden more canes, and if done properly, will allow some varieties of roses to form into a better garden shrub over the long term.

You can try to use this spring pruning and fertilizing to keep your roses a preferred size in your garden, but your influence is limited. I’ll put it this way: you’ll never make a small rose grow like a large rose by fertilizing, and you’ll never make a large rose grow like a small rose with pruning.

No matter your goals, it’s good to cut out dead, diseased and congested growth. And because roses are heavy feeders, they’ll respond well to a top dress of fertilizer or compost. A moderate amount of pruning and fertilizing will always leave your roses better off, and so I don’t get too hung up on the details… not even which other plants are blooming at the time!