My experience is that Squares are the unsung heroes of astrology. Most sites will say that they’re challenging or difficult, and they are, but they’re an amazing impetus for growth and progress. If we understand them, we can mindfully navigate our relationships and our own thoughts, feelings, and actions so that Squares become a source of strength, stability, and support. Squares are extremely stimulating, and the energy dynamic pushes us to resolve issues. Squares between current planetary placements in the sky (Transits) and our natal chart placements can be utilized to this end as well.
Squares are made up of Planets or placements in signs that are the same Modality. One sign in a Square is Yin and the other is Yang. The “easier” aspects such as Trines, Aspects, and even Oppositions are all Yin + Yin or Yang + Yang relationships. It may be helpful to think about it as a girl’s/guy’s night out vs a date or perhaps your relationship with your bff vs your relationship with your significant other. Yes, the same Yin/Yang polarity interactions are typically more comfortable, but the Yin + Yang interactions are no less important. They are more likely to make you sweat or to keep you lying awake at night, but they provide a great deal of motivation, growth, stability, effectiveness, and productivity in life. I’ve written about a similar topic here. Yin needs Yang, and Yang needs Yin. They support and protect each other.
In short, once we learn how to work with and balance out the energies, Squares are often, in my personal experience and understanding, an incredibly beneficial aspect! I have some Squares in my natal chart, but I’d like to offer this synastry chart as an example of how Squares can work:

The above chart is the synastry relationship chart. I’ve not written about synastry yet, but squares in synastry function similarly to squares in transits and natal charts. This particular synastry chart contains a Cardinal Grand Square. (Please note that this is not, however, a Grand Cross. They’re a different beast to discuss a different day.) Each of the red lines in this particular chart is a separate Square. This relationship has been both the most challenging and most rewarding experience of my life, and I’m a mother, so I’m not saying this lightly!
As an example of how Squares can be a debilitating weakness or an incredible strength, let’s look at the red Aries placements square the blue Cancer placements. Of course, charts are significantly more complicated than that, and it’s not possible to totally isolate one area of a chart, but my experience with this relationship highlights the dynamic that I’m attempting to explain quite well. For the purposes of this example, I’m just going to focus on the Signs, not the Planets or Houses.
Aries is the simplest of signs. It wants movement. It wants to win, and if its efforts are unrewarded by clear, measurable progress, it quickly gets frustrated and begins to push against whatever is standing in its way. It can be outspoken and even aggressive when faced with barriers or even minor delays. “Do do do, go go go! Outa my way!” and, “Are we doing this or not?!” and, “I’m going with or without you,” are mentalities we might see with Aries expression of energy. If Aries gets too impatient, it will just simply move on. “This is a waste of time. I’ve got other things to do.” It is the most shortsighted of signs, so it doesn’t think much about the long term or consider even somewhat far reaching consequences such as how its brusque nature can be hurtful and damage its relationships with others. It’s not malicious in and of itself, but it’s also not particularly thoughtful or considerate. Some say it’s selfish, and from a certain perspective, this is true. It’s not thinking about much of anything other than what it’s trying to do right now. It’s not that Aries thinks its values are more important than anyone else’s. It’s just not thinking about any of that! It’s Cardinal Fire, initiating and passionate. It’s also incredibly Yang: Active, outgoing, decisive, and dominating. A person with an Aries heavy chart can be warring and aggressive if there are not other energies at work in the chart to tame the person.
Cancer, on the other hand, is emotional, sensitive, gentle, nurturing, and guarded. The crab with its hard shell was chosen to represent Cancer for a reason! Some ancient systems used the turtle to represent Cancer. The turtle and the crab both have shells. Their home is important to them. They’re also not the speediest of creatures. The crab even moves sideways! Cancer is also very Yin: It’s passive in areas that aren’t particularly important to it, but it retreats into its shell when it feels threatened. It does not appreciate being pushed to do something that it’s not ready to do, and it’s very concerned with both protecting its loved ones and values and being protected. It needs stability from others to thrive because it’s moody. Its emotional state is everything, and its heart and therefore mind, demeanor, and behavior can change like the phases of the moon. During the darker phases, it can be pretty insistent on not moving. If you try to force it, you’ll find out exactly why those pincers are there! Cancer needs people to not only be patient and gentle with it, but also to provide stability and structure so that its free to indulge in its true feelings at any given time. It needs people who don’t take it too seriously, overreact, or abandon it when it lashes out or withdraws when its having a rough day or week.
I’m sure you can imagine how exasperated Aries could become with Cancer and how wary and thus uncooperative Cancer could be with Aries! How could any of this be a good thing?
Let’s remember that while Cancer is Yin, it’s also Cardinal. It wants to initiate and create, but it’s passive and introverted, so it can lack the necessary push to get its desires off the ground. Yin attracts others to take action. Aries, on the other hand, can push too hard and fail to reach its objectives due to impatience and lack of consideration for others. If we understand this, we can use that knowledge to see the situation from both perspectives and thus get past the initial hurdles. Aries must understand the cyclic nature of Cancer’s moods, refrain from overreacting to them, and give Cancer time and space when necessary with the faith that Cancer’s bright side will soon shine again. Aries must also refrain from pushing Cancer too much and allow Cancer to initiate indirectly through emotional expression. Once Aries understands this, it’s a fun challenge to stay present enough to spot Cancer’s cues that it’s time to act. There’s great satisfaction in meeting this challenge. Aries also benefits from the lessons it learns about how to patiently wait for the best time to move forward, how to notice and respect moods, and learning how to relax and allow itself to be nurtured.
Cancer, on the other hand, must trust Aries enough to express its feelings and desires and understand that Aries’ directness and even aggression can be tempered through proper communication. Aries can also be an excellent protector.This trust may sound simple, but it’s no small feat. What’s in it for Cancer? Aries loves to take action and make stuff happen, so Cancer can attract Aries and then harness some of this power to do by letting Aries know what it wants. Cancer can also learn to be more confident and from Aries, and it can become more comfortable with taking risks. When Aries and Cancer understand and are considerate of each other and work together, they can come to appreciate and even rely on each other greatly, and this creates stability. This applies in relationship charts as well as in natal charts. With transits, the Planet in question isn’t impacted like a person would be, of course, but the person involved can make use of the Square for growth.
Each set of Square Signs and each set of House and planetary placements has its own nuances, so consider all of that when looking at signs as well. Sun in Aries in the 2nd House Square Sun in Cancer in the 5th House is going to be a lot different than Mercury in Aries in the 11th House Square Moon in Cancer in the 1st House, as an example.
One of the ways to help the squared Signs or placements understand and work with each other is to focus on each Sign’s opposite (Capricorn for Cancer, Libra for Aries). In the case of a T Square where three of the Signs of the same modality are Square, focus on the fourth sign of that modality.
Of course, too much focus on one modality has pitfalls as well even when they are supporting each other well. A method for balancing that is to focus on the modality that follows the one on which there’s a natural focus in the chart. For example, the example above contains a Cardinal Grand Square, so it’s helpful to focus on the fixed Signs. There’s already a very strong focus on Scorpio due to my Moon and Uranus there and it being his Ascendant and having Pluto in Scorpio. There’s already a bit of a focus on Aquarius due to it being my Ascendant and South Node. He has Jupiter in Aquarius, but it’s intercepted, so it hadn’t been much of a focus for him before we knew each other. Meeting me did seem to bring him more into his Aquarius expression of energy! Taurus isn’t particularly pronounced in my chart, but his DC, Venus, and North Node are there. It’s an area in which I have put more attention since I’ve met him. My DC and North Node are in Leo, and Leo is also intercepted in his chart. This means that in our relationship, I would be wise to focus on Taurus and, even more so, Leo expression of energy, and he would be wise to focus on Aquarius, Leo, and especially Taurus expression on energy. (However, because Aquarius and Leo are intercepted in his chart, he must access them through the previous Signs, Cancer and Capricorn, but that’s a topic for another day.)