Thompson & Morgan Facebook Q&A Session 31st May 2013 - Your horticultural questions answered.

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Name: Steve Linden Wyatt

Question: Each year I buy hollyhocks but they never flower and never come back in the spring. Is there something special that needs to be done to get them to flower and as they are a perennial, come back?

Answer: Hi Steve, depending on how mature the plants are when you buy them they may decide to flower the same year, or they may wait until the next year, which normally gives an earlier display. They are fully hardy plants and are normally very reliable at returning the following year but could die if they’re suffering from a disease or waterlogged soil throughout the winter (e.g. heavy clay). The biggest disease of hollyhocks is rust, which causes yellow and orange spots to appear on the leaves and causes stunted growth. Plants which are suffering from this will lack vigour which could cause death, particularly in difficult growing conditions. Make sure you plant your hollyhocks in full sun and on free-draining soil. Heavy soils can be improved by working in compost or composted bark, or alternatively you could build a raised bed. I hope this helps Steve, best of luck with your hollyhocks!

Name: Kester Ratcliff

Question: I have some tuberose bulbs from T&M.; I planted them about 3 weeks ago in terracotta pots in multipurpose compost, watering regularly but not letting them get waterlogged, but still little or no signs of activity. (I've tipped one or two out of the pots to see if there was any activity underground, and most bulbs are still not even activated. But they're not rotted either.) I've got them in our loft room, which is very light and warm, but they only get direct sun warming the surface of the compost for a few hours a day. It's the lightest room in the house, but most of the time the sunlight is reflected off the walls rather than directly heating the surface of the compost.

The options I have available are- shed roof where they'd get direct sun most of the day but be cold at night, or on top of the hot water tank where they'd get continuous warmth from underneath the pots but be in the dark (and I can't fit all the pots on top of the tank!). Which would you guess would be better? Warmer but dark, or more sun direct on the surface of the compost and cooler at night? Or I could tip some of the compost out so the tips of the bulbs are exposed to light, then if/when they've sprouted put more compost back in around the bulbs so they don't tip over when they grow taller (that worked with my Canna lily)? Thanks!

Answer: Hi Kester, Tuberose bulbs take a long time to get started so don't worry just yet! It sounds like you have them in a good location. They like to be planted underneath a few inches of compost so I would advise against exposing the tips of the bulbs. They prefer warm growing conditions, with a minimum temperature of 15°C (59°F). The shed roof may be too cold at night for your Tuberose so I wouldn’t put it there, but an airing cupboard or similar would be fine, provided temperatures don’t rise above about 30°C (86°F). It doesn’t matter whether the location is dark or light while the bulb emerges. As you have been doing, keep the soil moist but not wet, letting the top inch of compost dry out between watering. Hopefully you should see some signs of life soon. Let us know how you get on!