Dealing with planting delays

Planting delays are risky for seedling survival. If you need to delay planting trees on your site, there are some things you can do to help your seedlings survive.

The ideal time to plant trees in New Zealand is during autumn to spring. At this time, the soil is moist enough for the seedlings to establish.

Planting tree seedlings outside this timeframe is risky. New seedlings need water to survive. Planting closer to summer means the seedlings establish during the dry summer months. This puts them at risk of not getting enough water (water stress).

Can you delay planting?

There are some reasons you may need to delay planting. COVID-19 lockdowns caused planting delays. The spread of COVID-19 saw a lot of the workforce off sick too.

Climate change will also cause delays. As the weather changes, the ideal planting timeframe may become shorter. You may also have to deal with droughts or flooding.

The biggest risk for planting delays is the seedlings dying. There are several ways to help seedlings survive delays to planting.

Research into COVID-19 planting delays

COVID-19 lockdowns caused planting delays in the forestry industry. Research into the effect of the delays found techniques to:

  • help seedlings survive planting delays
  • help you hold stock for longer
  • look after a site you’ve prepared for planting but can’t plant on.

Below is a summary of the techniques and research informing them.

Holding nursery stock

If you’ve ordered stock but can’t plant it, you may be able to slow down its growth with these methods.

  • Topping – trimming the top of the plant to stop it growing upwards. This is only practical for certain species like shrub hardwood species.
  • Collecting and storing more seed to provide flexibility. This risks seeds becoming less able to germinate (grow) over time.
  • Repotting into larger containers to hold stock until the next planting season.

Controlling seedling access to nutrients and water can help prevent too much growth in the nursery. It also prepares crops for lifting, storing and planting.

Look after a site you’ve prepared for planting

There are few ways to look after your site if you need to delay planting.

  • Use herbicides to stop woody weeds growing on the planting site.
  • On pasture sites, make sure grazing continues.
  • Plant grass on bare sites to stop woody weeds growing during the delay.

Read the fact sheet

Keeping seedlings alive

It’s possible to extend the planting season and make it successful by doing a few things.

If you need to delay planting, help keep seedlings alive by:

  • growing them in containers
  • moving them to the planting site using refrigerated transport
  • having small regular deliveries made to site
  • using larger crews to speed up planting
  • planting larger stock, which may be more resilient to delayed planting
  • using plant guards to protect the plants
  • using mulch to keep the soil moist
  • choosing hardier species to plant
  • avoiding problem planting sites.

Read the fact sheet

Delayed planting

Manaaki Whenua – Landcare Research developed 5 steps for planting success. These steps help seedlings survive tougher conditions, like delayed planting and drought.

  1. Assess the site to choose the best location for planting. Looking at the soil helps you understand how the soil behaves and how it may affect your seedlings.
  2. Select your plants. Choose plants resilient to drought conditions. Ask nursery staff for help if you’re not sure.
  3. Prepare the site. Understanding your site will help you know what site preparation to do. Does the site need weed control? Is there mulch on site you can use to keep moisture in the soil? Do you need nurse plants to protect your seedlings?
  4. Planting techniques are important for success. Water your plants before and after planting. Don’t plant your seedlings when they’re dry. Think about using plant guards to protect your seedlings while they grow.
  5. Create an ongoing maintenance plan. How will you manage weeds? Do you need to use mulch? Is protection from browsing animals needed? Would nutrient rich wastes benefit your site?

Read more about using nutrient rich wastes for forestry plantings.

Read the fact sheet

One Billion Trees research fact sheets

This research was commissioned by the One Billion Trees programme.

Read about other One Billion Trees science projects on the Ministry for Primary Industries’ website.