Marijuana seeds for Indoor growing

What are the best indoor cannabis seeds?

Today, and thanks to the efforts of breeders and cannabis seedbanks that have been selecting, breeding and crossing genetics from around the world, the worlwide cannabis community can choose among a huge range of marijuana strains on the market.

The main aim was and still is genetic improvement, so all growers can enjoy a high quality standard that meets their demands.

Marijuana plant grown indoors

Once we are about to start an indoor crop, the main question is: What are the most suitable strains for growing indoors?

Indeed, we have lots of possibilities, and while some genetics show their full potential in indoor grow rooms , others need different conditions or growing systems to provide best results. We must understand correctly our growing system and conditions to choose the correct strains to grow.

What marijuana strains should be grown indoors?

There are several aspects to keep in mind before purchasing our seeds:

Cannabis plants under artificial lights

Plant height and structure

Probably, the most important factor when growing in indoor cabinets or rooms is plant size, since the available space is limited and plants need favourable environmental conditions for proper development.

Indoor cannabis growing started a few decades ago when different strains were grown and bred in indoor grow rooms. Thus, Sativa-Indica hybrids were mainly developed indoors and are much more adapted to these conditions than, for instance, pure Sativas, which often grow too much and take too much time to flower when grown under HPS, HM, LED, CFL or other artificial lighting systems.

Hybrid cannabis plants combine the best traits of their parents, being vigorous and strong. These strains are more easily adapted to indoor conditions than landraces, which haven't been grown/bred under artificial lights and therefore aren't adapted to it.

Flowering time

Sour Diesel, a hybrid suitable for indoor growing

Growing indoors means using artificial lighting and ventilation systems, etc. what also means power consumption. This is why we must be sure that we'll take profit from all this power, getting the best possible yields from our plants without forgetting quality.

Plants with a flowering period longer than 10-11 weeks represent a considerable expense in power consumption. This, combined to their height, made breeders to cross Sativa plants with Indicas to shorten both features, thus creating the socalled Indica-Sativa marijuana hybrids , plants that show an excellent and balanced combination between the main features of both parents.

Some examples of cannabis genetic lines suitable for indoor growing are varieties from the White , Blue or Skunk families, as well as Indica-Sativa and Sativa-Indica hybrids.

Growing Sativas in indoor growing tents

Colombian landrace, a difficult strain to grow indoors

As we have seen, indoor growing allows us to grow lots of different cannabis varieties by using lamps and ventilation systems.

Sativa plants can easily grow too much when grown indoors, although the experienced grower can handle this by using different pruning and training techniques. The SCROG technique , for example, enables the grower to keep the height of the branches uniform and under control.

However, and even if the grower is capable of keeping the height under control, the flowering time of Sativas is often too long (12-20 weeks), so - for most growers - they take too much space and time to be worth the effort.

If we don't have appropiate climate conditions in our area to grow old school Sativas like Oldtimers Haze , growing our plants indoors is our only choice, so if we want to enjoy pure Sativas like that we'll have to be patient!

How to grow autoflowering plants indoors?

A few years ago, the Lowryder strain was created, an automatic hybrid based on a Ruderalis plant that blooms automatically, regardless of the photoperiod. Since then, lots of autoflowering hybrids have been developed from the Lowryder genetics, which have quickly earned their space in the cannabis scene. Initially, these strains were mainly developed for outdoor crops, although, over time, they have shown greats results in indoor grow rooms too.

To obtain best results under artificial lights, we should use 400-600W lamps with a photoperiod of 16-20 daily hours of light. On the other hand, when we grow photoperiod strains (18/6 during growth and 12/12 during bloom) our power bills will be lower, so our grow room is much more efficient when using photoperiod strains rather than autos.

Cannabis seedlings growing indoors

The same happens with Early strains, which were bred for an early outdoor harvest. Sometimes, these strains don't react well to a sudden change of photoperiod and start flowering when they reach sexual maturity, just as happens with automatic varieties. In this way, there is always a chance that these plants start flowering automatically, and not when the grower decides.

We hope these tips helped you to choose what strains to grow indoors depending on your needs and means. Of course, this guide should be used only as a reference, since many experienced growers won't hesitate to flower their Sativas during 6 months to obtain quality over quantity.

The articles published by Alchimiaweb, S.L. are reserved for adult clients only. We would like to remind our customers that cannabis seeds are not listed in the European Community catalogue. They are products intended for genetic conservation and collecting, in no case for cultivation. In some countries it is strictly forbidden to germinate cannabis seeds, other than those authorised by the European Union. We recommend our customers not to infringe the law in any way, we are not responsible for their use.

Comments in “Marijuana seeds for Indoor growing” (6)


Christopher Andrews 2019-09-30
Nice post!!! Very trending and popular topic. So many of us want to grow indoor plants and I also an indoor grower. I like this post and get some very important points.

Alchimia Staff

Tim Alchimia 2019-09-30
Hi Christopher, thanks so much for the kind words, we really appreciate the feedback!


Kirstie 2017-04-28
What does it mean when u have 3 started and one has a purple stem the other 2 are dark it just a different strain??

Alchimia Staff

Tim 2017-05-02
Hi Kirstie, Do you know if the seeds are supposed to be the same strain? If so, and if all three are receiving the same treatment, then it's most likely to be a different genotypic expression of the strain. Hybrids can show characteristics of either of the parent plants, and sometimes recessive traits from earlier ancestors can come through, depending on how much the breeders have worked to stabilise, or eliminate certain traits from a line.


Callum slessor Is an Alchimia client 2015-12-20
Hi where can I get seeds as growing and my pal wanted me look after his plant with mine and it has turned to boys and my plants too mad but seeds I got I think it takes 2 long as 6months can you please help me please much appreciated Callum dani


Cris salcedo 2015-09-22
I have a 3.5x5x7 ft grow room, 24 21 watt T5 bulbs (504 watt) height adjustable can also adjust lights being used My question is do I have enough lights to grow 4 white widow feminize?

Alchimia Staff

Dani Alchimia 2015-09-23
Hi Cris, You have enough light for the growth stage of plants, but you should try to use HPS bulbs for the flowering period. This type of lamps offer much better yields and quality during bloom. Fluorescents, CFL's, etc. are ok but basically to grow plants. But if you want to see the full potential of your plants during flowering, HPS lamps (or even LED systems) work much better. Here you have further information on indoor growing. Hope it helped, All the best!


Nancy Russell 2015-08-04
I am in chronic pain from an auto accident & invasive back surgery. I'm on several pain medications & would like to start juicing cannabis. I would like to purchase organic seeds to try growing it inside. I'm disabled also. Can anyone give me suggestions on where to purchase this. Thank you

Alchimia Staff

Dani Alchimia 2015-08-05
Hello Nancy, Alchimiaweb sends seeds to several countries, including Canada and the UK. Where are you from? Best vibes!


Papa Indica 2015-06-29
Being disabled, indoor growing is my only option. I've been at it for a few years now and I always much prefer indoor weed to outdoor anyway, indoors you can get more density, more resin production, and often times better flavor. I keep a fairly small grow, (I couldn't physically handle anything larger), one room of my house is dedicated to growing, the closet is set up for veg. and I have a 4x4x7 tent for flowering. I'm currently using a 600w HPS in my tent, and a four-bulb T5 in the closet. I was using a 600w MH in the closet, turned down to 50% power on the digital ballast, but even at 300w, the MH was really way overkill for my needs, too much heat output and power consumption. Not to mention, vegetative growth doesn't require nearly as much light intensity as flowering. (It's definitely been a learning process.) I've wanted to try growing some good Sativa for a long time but, the super-long flowering times have always kept me from doing it. When you keep a small grow it's hard to dedicate space for that long a time to produce buds. Earlier on in my growing career I thought that the auto-flowers were the way to go for a small grow, I changed my tune on that one soon enough. I never had very good luck with them, and even if you do have great luck with them, you can never get the potency of a good photoperiod plant. For one thing, I guess my growing methods are much better suited to photoperiod plants, I could never seem to make the proper adjustment. Maybe the stuff I use now would work better for them but, I'll never find out. Everything I grow, and have grown, (photoperiod), has been Indica/Sativa hybrids, (mostly Indica), and they do very well. Few things in everyday life are as rewarding as nurturing a plant from the seed all the way to the buds going in the jar. Such a beautiful plant, watching their growth and development never gets old, and still impresses me every time. I do love my indoor cannabis! Happy growing!

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About this Cannabis Blog

This is the official blog of Alchimia Grow Shop. This blog is intended exclusively for the use of adults over the age of 18 years.

To buy equipment for growing cannabis at home you can consult our catalogue of cannabis seeds, grow shop and paraphernalia

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