Direct Seeding vs Tubestock Planting
When it comes to rehabilitating degraded landscapes there is often the ye ole question that inevitably rears its head. Should we Direct Seed or plant out Tube Stock plants? So please let me help...
Direct seeding is of course cheap and tube stock planting is of course much more expensive....or so one may choose to initially believe. Let me explain.
The risks associated with direct seeding native grass, shrub and tree seeds are; (amongst others)
- Once applied to the soil the seeds can be transported away by ants - who would of thought!
- If the seeds hang around and get a little wet from a small rainfall event or a less than adequate irrigation regime they can imbibe (absorb water) and then rot. If the seeds actually do germinate but then don't have enough follow up water given to them in this initial stage of life the seedling will dehydrate and perish.
- Seeds can also be easily washed away (if placed in waterways)
- The land can, while waiting for your native seeds to germinate, be overtaken by weeds and/or erode
- And then there is the question on the quality of the seed you or your contractor has purchased (or collected). Is it viable? Has it had a viability test?
You see native seeds need, in order to germinate TIME, TEMPERATURE and MOISTURE all in the exact quantity and relationship with each other to perform.
And each species has its own TIME x TEMPERATURE x MOISTURE relationship requirement…..getting tricky isn’t it?
Native seeds also need the surrounding environment to be in a particular condition and void of threats (erosion, wind, heat, animals, water-flows).
And of course the seed needs to be ready and able to germinate (VIABLE). ......and it can be impossible for you to know all of this.
So when looking to obtain quick results for your landscape rehabilitation project the direct seeding approach has
many factors (risks) that can conspire against you.
But having said this let’s not forget the wonderful advantages the direct seeding approach can offer. (IF it
- It’s cheap
- A plant grown from seed on your site can outperform (in the long run) any planted plant
- A plant grown from seed will (for some strange reason) be less prone to attack by birds – I know weird hey?
- Because its cheap you can rehabilitate a lot more degraded land for your money (IF you have properly dealt with and mitigated the risks)
When using Tube Stock plants to rehabilitate your degraded landscape you tend to know and can see what you are getting for your money and more importantly, unlike seeding operations, can reasonably hold your contractor to account for success…and this is important to note…the tube stock planting strategy offers you ACCOUNTABILITY while the seeding strategy may not.
So when to seed and when to use tube stock plants?
Seeding can work well on sites that;
- Contain low nutrient soils (remember higher nutrient soils, like ex dairy or grazing lands, means more weeds to deal with and less diversity)
- Are bare soil (like recently excavated or covered ground. i.e.; quarries or mine sites)
- Enjoy low weed pressure from neighbouring sites
- Are flat and have no to minimal erosion potential
- Are not in a watercourse
For seeding to work well the risks mentioned above also need to be dealt with…..and there are ways to do this!! - ant bait, use of sterile cover crops, hydro=mulching, jute netting, germination testing, seeding timing, irrigation monitoring, properly sized and placed erosion and sediment control devices, soil amelioration techniques, proper site selection, detailed weed follow up control programs, site germination monitoring are but a few of the strategies that can be employed.
Seeding is good also when there is a shared pain and gain contractual relationship between the client and the
If however most if not ALL of the above factors cannot be properly dealt with, and you want to hold your landscape rehabilitation contractor completely liable for success, then tube stock planting is the way to go for you!
If you are pondering any of this and need help I am on standby to ensure your strategy and your scope of works gets it all right the first time and your project can be delivered on time and on budget with the minimum of fuss!.
Published on behalf of Dean Chaloner - General Manager at Aust Care Environmental Services Pty Ltd