When to Fertilise and Feed your Brisbane Plants

When to Fertilise and Feed your Plants!

As a nursery specialising in indoor plants, tropical plants, succulents and rare plants, we get a LOT of questions about fertilising. When? How much? What type of fertilisers for which plants? 

Unfortunately it’s not as simple as chucking a general, one-size-fits-all fertiliser about the garden once a year, particularly if you’re buying orchids or indoor plants, but part of the fun of gardening is learning the rhythm of these things (Or that’s what we think anyway!)

It’s really not too complicated once you learn some basic rules about fertilising, and get to know your plant’s requirements to make it thrive. So, let’s break it down into some of the most common questions about fertilisers that we encounter here at The Tropic Gardener. 

When Should you Fertilise your Plants? 

Really, you should be fertilising your garden at least three times a year (plant dependent), but if you only seem to get around to doing it once, then spring is absolutely the winning contender- even more so if the plant is growing or forming its buds or fruit. 

Fertilising in spring is hugely important. Plants put on heaps of growth in spring, and need to be in tip-top health as they enter the blazing hot summer months, whether indoor or outdoor.

When in spring? Early spring is best, particularly here in South East Queensland where it gets hot pretty fast!


The Fertiliser Basics: Nitrogen, Phosphorous, Potassium. (Know Your N,P,K!)

N: Nitrogen encourages leafy growth.
P: Phosphorus encourages overall growth.
K: Potassium boosts flowering. 

A ‘balanced’ or ‘complete’ fertiliser is an all-rounder with all three of these components, but be mindful: some plants need different levels of each of these. For example, citrus will want heaps of phosphorus and potassium, while native plants don’t like phosphorus at all!  

Seasol and similar seaweed-based fertilisers have little to no nitrogen. Good fertilisers will also have small amounts of the sulphur, calcium and magnesium that plants need to thrive.

Fertiliser labels will always help you out with the levels of N, P and K, and there will be recommendations for which types of plants they’re for on the package and the dosage schedule. If in doubt, give us a call. 


How does Caring for Plants in Brisbane Differ from Other Regions? 

Plants growing in subtropical gardens like here in South East QLD  will often need more regular fertilising, as our hot, wet summers and tropical downpours tend to leach the nutrients from the soil faster than in drier climates.

How soon after you get a plant delivery from us should you fertilise your plants? 

We have a physical nursery here in Kenmore Brisbane, but we’re also an online nursery posting plants Australia-wide (excluding quarantine states). You’ll want to either pot or plant your new plant straight away upon delivery, and pot it with a good quality potting mix that has slow-release fertilisers built-in. You don’t need to add other fertilisers yet, as you will risk over-fertilising. Let the plants ‘eat up’ that initial food before fertilising again (generally 1-2 months, but check your potting mix for details).  

We give instructions on how to care for your plants after delivery, so please read them to ensure you don’t shock them after they’ve been unboxed!

Fertilising Your Indoor Plants

When you put a plant in a pot, it has a limited amount of food. Unlike garden plants, potted plants can’t put out new roots to find nutrients, and it is totally dependent on you (and your memory) for food and water. It’s like a baby! You need to top it up...but here’s the kicker: a lot of indoor plants will want different regimes, and many keen indoor gardeners have killed their plants through ‘too much fertiliser love’.

The rare anthuriums we sell, for example, will only want to be fertilised twice a year, while plants with really big, dramatic blooms will often need more frequent fertilising. 

Do your research on your plant’s fertiliser needs, and if you get stuck, we are here to help. 

So, which fertiliser should you use for indoor plants? 

Firstly, we generally recommend steering away from granular fertilisers for indoor plants, as they get ‘watered in’ instantly and you can’t control the dose, and it’s also hard to get them dispersed evenly through the soil. 

We suggest liquid fertiliser or slow-release fertiliser. The benefit of slow release fertilisers is that you can get ones that last 6-9 months, meaning you don’t need to feed them regularly. (And if you’re a bit forgetful or time-poor, this is a great option!)

However, with liquid fertiliser that you dilute with your regular watering schedule, you do get to control the dose more, that is, you can suspend your fertilising regime during winter when the plant is dormant. 

We’ve got a great range of indoor plants for sale, check out our online nursery.



Fertilising your Succulents

This is an easy one, as succulents don’t need much fertiliser (which is why they’re perfect for new or time-poor gardeners). One dose of low-nitrogen fertiliser in spring will do it for the year. 

We’ve got a great range of succulents for sale Brisbane, check out our online nursery


Fertilising your Tropical Plants

So, we’ve already said that Brisbane garden plants need more fertilising because nutrients leach away during summer downpours. It’s also important to know the positioning of your plants for their fertilising needs. For example, plants in direct sunlight often need higher doses of fertiliser, while those in the shade benefit from smaller doses, more often.

If you don’t want to fertilise regularly, use a slow-release, whether liquid or granular. And remember, if you’re fertilising every time you water, have some clear-water waterings every week to 10 days to wash away any salt build up or excess nutrients. 

Remember that tropical plants native to Brisbane that are planted in the garden and get lots of leaf litter and have good mulch cover will need less fertilising, as this is their native environment.

We’ve got some stunning tropical and subtropical plants here at the nursery, check out our online shop!


Fertilising your Orchids

We are the place to buy orchids in Brisbane- we’re mad about them! They are splendidly greedy on the fertiliser front, with weekly demands- but remember, weekly and WEAKLY- use a half solution of a balanced liquid fertiliser. (Remember your NPK’s!).  

Fortnightly fertilising in cooler months should be sufficient. Fertilise in the morning to aid photosynthesis and to avoid the roots being soggy overnight. 

We’ve got a great range of rare plants for sale including orchids, check out our online nursery.


Must-Know Tips About Fertilising

  1. Don’t over-fertilise! This is massively important, as plants will suffer even more from over-fertilising than they will from getting no fertiliser at all.
  2. Don’t get fertiliser directly on the roots. If you’re fertilising at the same time as planting, then make sure you fertilise the ground, then add a layer of soil before placing the plant in the hole so the roots don’t directly  touch the fertiliser, or just really work that fertiliser through the soil. (We’d normally recommend you fertilise the ground a week or so before planting, but this way will work too.)
  3. Water the ground around the plant thoroughly before applying the fertiliser,  then water it in afterwards too. 
  4. Dilute the fertiliser according to the instructions; use a watering can for liquid fertilisers.
  5. Keep your fertiliser in a sealed container, away from sunlight, kids and pets!  


Confused? Need more help? Just call us, or drop into our Brisbane nursery at Kenmore. We love a bit of plant-chat!