How To Plant Bare Rooted Roses In Passive Greenhouses

Roses are beautiful flowers whether they are in a garden of in a vase.

Flower arrangers all over the world really enjoy using roses as the base flower of their display.

This eye catching flower is mostly grown as a bush both in protected environments like greenhouse or tunnels and in open flower gardens.

There are two methods of planting roses are the use of Speedling  or bare rooted roses. In this article, we will look at planting of bare rooted roses in a greenhouse.

Bare rooted bushes have the following characteristics:-

i) They are sold with their roots exposed due to absence of soil or container.

ii) They require more careful handling during planting.

iii) Bare rooted bushes  are usually large and vary in size depending on the variety. They may need more time and care to establish themselves in the garden or a greenhouse.

iv) They may have limited availability and options as they are sourced from specialty rose growers or very special plant nurseries.

v) They are planted during the dormant season only, which is late autumn to early spring.

vi) Bare rooted roses bushes must be at least 6 months old for them to be ready for planting.

Let look at how to plant cut roses using bare rooted planting material.

1. IRRIGATION

a) The Facility– The irrigation scheme is based on drip irrigation with a venturi or hydraulic pump, to introduce the nutritional requirements.

Before planting out, the whole system must be field treated and initial calibration of the venturi completed. It is very important that during that during fertigation, the fertilizer is introduced at the start of the set and finished at the end of the set.

This is important at all times, but particularly so with young newly  growing roots from about 7 days after planting out. Thus , time taken to calibrate the fertigation system ahead of time is essential.

b) Pre-Planting Irrigation– It is important the whole bed profile is at field capacity before planting. This will be best achieved by overhead irrigation. To ensure an even distribution, apply the irrigation in three sets to achieve field capacity.

2. BED PREPARATION

a) Bed Making 

The objective is clear- to have beds made to a consistent settled height of 35 cm with extra care taken to maintain absolute level bed tops and evenly draining pathways. Endeavor to achieve a full 80 cm wide bed top.

b) Marking Out Planting Stations

Here the objective is to plant +-62000- 65000 bushes per ha. The bushes are set in 2 rows per bed.

The rows should be aligned as far apart as possible( with careful bed making, this distance can be 45 cm however, 35-45 cm are acceptable, with the plants at least 10-15 cm in from the edge of the bed).

Between row distances must be consistent throughout, so for example, if the beds along the greenhouse pole line cannot accommodate 45 cm between the line spacing, then reduce all between line distances to the potential on the narrow beds.

The distances between plants in the row are calculated by dividing the total length of the bed top by the number of plants planned for the planting eg on a 1 ha greenhouse you are likely to have 145 beds x 40 m long = 5800m bed top.

You plan to plant 62000 plants per hector. 5800/62000=0.09m x 2(since there are 2 lines) =0.18 or 18 cm between plants.

3.PLANTING OPERATION

Dig two planting trenches at least 25 cm deep, approximately 35 cm apart, on the level 80 cm wide bed top.

Endeavor to complete all preparations 24 hours before the planting material arrives on the site. Upon arrival, plants should be immediately placed into the cold room to reduce potential transport shock.

Aim to set the plants into the greenhouse as soon as is practical. However, keep the plants stored in the cold room at 2 degrees Celsius.

Gradually bring the plants up to ambient temperature to help reduce transplanting shock, prior to planting. When plants are taken out of their containers, all sub standard bushes must be separated and discarded.

Place the bushes in the planting trench, gently aligning the bare roots along the trench.

Ensure that the graft union is always facing outwards when placing the bushes in the trench. The reason for this is for ease of bending of the new growth.

Gently cover the roots in the trench and firm lightly.  Immediately after this the plants should be thoroughly watered (with hose and rose ) to set the soil around the roots and remove any air pockets.

After setting, the plants ( including the whole plant portion above bed level ), the whole bed top and the bed shoulders must be covered by a thick layer of mulch (which ideally  should be fumigated).

An additional heavy application of water (hose and rose) will be required to thoroughly wet the mulch in order to maintain a humid environment around the bushes.

4.AFTER PLANTING CARE

i) Day 1 and 2

Every effort at this stage must be taken to eliminate sunburn of newly planted bushes. Mist ( hose and rose watering ) the beds and the pathways 3-4 times daily. If there is any doubts as the moisture status of the beds, apply water through the main irrigation channel. Stagnant water should not cause any harm.

ii) Day 3 to 6

Continue misting daily, remembering not to reduce humidity. The drip irrigation facility should be switched on at this stage to start establishing an irrigation pattern. Apply an amount equivalent to 2mm/ day / hector through the drip (= 20m3 water /day/ha). Please note this amount is dependent on soil type.

iii) Day 7 to 9

Continue to supply the majority of the plants water requirement through the drip. Misting of the beds and pathways should continue to maintain a high humidity around the plants, however the frequency may be reduced once the roots are actively growing.

iv) Day 10 Onwards

Approximately 10 days after planting, shoots may start to develop. Do not get too anxious, as this is not always an indication of plant health/vigor or successful planting (buds, shoots, eyes often burst due to high humidity/temperature).

Do not be tempted to remove the mulch at this stage either. Inspect the bushes root development by carefully removing soil away from the root zone. When fine, hair like feeder root development on the older roots are evident, a successful take has been achieved.

It is now time to start feeding the bushes a dilute fertilizer mixture through the drip. Gradually start removing mulch over a period of 10-12 days.

It is advisable to continue misting the bed tops and shoulders daily, to maintain an adequate moisture status across the whole bed profile.

5. Summary

For successful transplanting, the preparations before planting are all important. The main points are:

i) Good bed preparation

ii) Careful pre-irrigation

iii) Accurate marking out of planting stations

iv) Careful transplanting including plant selection.

v) Even mulch distribution and frequent light hose and rose watering until new active root growth are evident throughout the planted area.

The main threat to the success/failure of planting 6 month bushes is the ability to maintain adequate moisture in the soil and a high humidity in the micro-climate surrounding the plants.

Mistakes are commonly made by removing the mulch and reducing the misting prematurely, upon visual bud break of the bushes.

It cannot be stressed enough that new root activity and development are the key to successful planting of 6 months bushes.

Take away

By following this simple guide, I can guarantee success of establishment of bare footed rose bushes in a greenhouse or tunnel.

If you have questions or need further clarification please do not hesitate to leave a message in the comment box below.

Happy growing of cut roses.