Seed rais­ing 101

Rais­ing plants from seed is a cost-ef­fec­tive way of plant­ing out a gar­den. Al­though it’s faster and eas­ier to buy seedlings from a gar­den cen­tre, grow­ing from seed al­lows you to choose more un­usual veg­eta­bles and cre­ate back­yard bio­di­ver­sity.

NZ Lifestyle Block - - Growing - Words Emma Raw­son

For a seed to ger­mi­nate and grow into a plant it needs:

Soil or a grow­ing medium Seed-rais­ing mix is ideal; a light soil mix that in­cludes pumice and nu­tri­ents that en­cour­age seedling growth.

Mois­ture Wa­ter ac­ti­vates the bio­chem­istry of the dor­mant seed em­bryo.

Tem­per­a­ture Plants will ger­mi­nate at a heat sim­i­lar to its ideal soil tem­per­a­ture (see our crop grow­ing tips on page 26), al­though a warmer tem­per­a­ture will speed up growth. Keep­ing a plant at a con­sis­tently warm tem­per­a­ture (in a green­house or hot wa­ter cup­board) will fast-track ger­mi­na­tion.

Soak­ing and scratch­ing

Some larger seeds or seeds with hard ex­te­ri­ors, such as beet­root, need to be soaked be­fore plant­ing to help the plant em­bryo to break free. These seeds are of­ten from plants na­tive to ar­eas with cooler win­ters. The tough ex­te­rior is de­signed to pro­tect the seed against harsh tem­per­a­tures. To soak, sub­merge the seed in cold wa­ter for 12-24 hours. Any longer and the seed will rot. Seeds that might re­quire soak­ing in­clude beet­root, peas, beans and corn. Some seeds, such as pump­kins and squash, like to be scratched or ‘scar­i­fied’ with a nail or emery board to mimic the ac­tion of an an­i­mal gnaw­ing on the seed. The outer cas­ing is a bi­o­log­i­cal ad­van­tage to pro­tect seed from her­bi­vores.

Light or dark

The ma­jor­ity of seeds pre­fer dark­ness to ger­mi­nate. A hot wa­ter cup­board is ideal for seed ger­mi­na­tion. How­ever, some seeds such as let­tuce pre­fer light.

How deep?

Aosw a g rule, plant a seed no deeper than twice its di­am­e­ter. As a gen­eral rule, plant a seed no deeper than twice its di­am­e­ter

Seeds planted too deeply will not reach the sur­face be­fore their food re­serves run out.

Fine seeds, such as let­tuce or cel­ery, only need to be scat­tered on the sur­face and gen­tly pressed into the soil.

To avoid wash­ing away seeds when wa­ter­ing, moisten the soil be­fore plant­ing, then con­tinue to moisten daily. Us­ing a wa­ter sprayer wets the soil with­out over­do­ing the wa­ter­ing.

Check seed pack­ets for ger­mi­na­tion time – when seedlings start to emerge, move them to a spot with nat­u­ral light.

Thin­ning is win­ning

When seeds have ger­mi­nated, thin them out to pre­vent over­crowd­ing. This is the time to be ruth­less. Pull out weaker seedlings to let larger ones thrive. Move seedlings to a big­ger pot when the first true leaf emerges.

How to pre­vent shock

Grad­u­ally ac­cli­ma­tize a plant to the out­doors. Move it from a win­dow sill to a spot un­der a cloche, be­fore ex­pos­ing it to the el­e­ments.

Be care­ful not to dam­age root sys­tems when re­mov­ing a seedling from its tray. Seaweed ex­tract will stim­u­late root growth.

Plant­ing seedlings in biodegrad­able peat pots helps avoid root dam­age. They can be costly, so try mak­ing your own (see page 26).

Newspapers in English

Newspapers from New Zealand

© PressReader. All rights reserved.